Outlook and Microsoft 365

For: Account owners and administrators·Requires: The Admin permission in Replyco and a Microsoft account with a mailbox; every plan·Screenshots show sample data

A shop whose customer service runs on Microsoft 365 or Outlook.com wants every customer email handled as a ticket and every answer sent from its own address. The Outlook account connects that mailbox to Replyco with Microsoft’s own sign-in: customer mail arrives as tickets, your replies go out through Microsoft from the mailbox, and the folders you choose decide which mail becomes a ticket.

What it does

A Microsoft mailbox holds customer questions next to deleted mail, sent items, newsletters and meeting notes. Answered from Outlook alone, the team shares one inbox with no assignment and no history per customer; forwarded to a helpdesk, the replies stop coming from your address and strict recipients start rejecting them.

The Outlook account signs in to the mailbox with Microsoft, so Replyco reads and sends mail through Microsoft’s own interface. Every Outlook conversation becomes one ticket, and your replies are sent by Microsoft from the mailbox, as answers in the same conversation. From there:

• You choose what becomes a ticket. Leave the folder choice empty and Replyco imports every folder except junk, or pick folders such as Inbox or your own Returns folder. See understanding folder sync and every setting, explained.
• Read state stays in step. Opening a ticket marks its messages read in Outlook, and marking it unread does the reverse. See Outlook in your tickets and your mailbox.
• Replies come from your address, in the customer’s conversation, and appear under Sent Items. See replies.
• A lost login is visible and quick to fix. When Microsoft stops renewing Replyco’s access, the account shows Blocked with the reason, and Re-login signs in again. See reconnecting a blocked Outlook account.

Replyco keeps the time of every sync and the reason of every block on the account, in its details under Admin›Accounts, so a quiet mailbox can always be traced to a date and a cause.

Before you start

Requirement	Details
Plan	Outlook is part of every plan. Each Outlook account counts as one account against the number of accounts your plan allows; when it is reached, + Add Account disappears from the top bar. See What each plan includes.
Who can connect it	Users with the Admin permission: the Admin menu, with Admin›Accounts, appears only for them. See User permissions and roles.
A Microsoft account with a mailbox	A work or school account in Microsoft 365, or a personal Outlook.com or Hotmail account. Replyco connects the mailbox of the account you sign in with. A mailbox on your own Exchange server cannot be connected this way.
Microsoft’s permission	Microsoft asks you to let Replyco read your profile, read and change your mail, send mail as you, and keep that access. Some Microsoft 365 organisations let only their administrators approve apps; then an administrator approves Replyco first.
A shared mailbox	A shared mailbox has no sign-in of its own, so it cannot be connected as an Outlook account. Forward its mail to Replyco instead; see Mailbox by forwarding.
Who sees the tickets	Every user of your company gets access to the new account’s tickets. To limit an account to some users, see Users.

Good to know

The Outlook account needs no mail server settings, app password or DNS records, and it works where Microsoft no longer accepts passwords for SMTP. There is no name to type either: Replyco names the account after the mailbox address and sends with the name Microsoft has for the mailbox.

Understanding folder sync

The box Sync Messages from Folders: lists the mailbox’s top-level folders with the names the mailbox shows, in its own language: Inbox, Sent Items, Deleted Items and your own folders such as Returns. Your choice decides what Replyco imports:

Your choice	What Replyco imports	Typical use
Nothing chosen (the default)	Every folder, including the folders inside other folders, except Junk Email and drafts	A mailbox that only receives customer mail
Inbox	Mail directly in Inbox	Leave out sent, deleted and archived mail
Inbox and your own folder, such as Returns	Mail directly in either folder	An Outlook rule moves returns requests into their own folder
Your own folders only	Mail directly in those folders	A mixed mailbox where rules move customer mail into a folder
Select all	Mail directly in every top-level folder, Deleted Items and Archive included	Rarely wanted; leave the box empty instead

How Replyco decides

• About every five minutes Replyco asks Microsoft for new mail. A newly connected account is synced before the others.
• One ticket per Outlook conversation. A new message joins the ticket of its conversation, then a ticket you started with the same subject that has no reply yet, then, if you switched it on, a recent ticket of the same customer; see Specific Account Settings.
• Folders are matched by name. Replyco looks up the chosen folders by their names on every sync. Rename a folder in Outlook and choose it again in Replyco.
• A chosen folder means that folder. Mail in a folder inside a chosen folder is not imported; choose nothing to import every folder, inside ones included.
• Your own mail is your team’s. Mail sent from the mailbox arrives as a message of your team. A new email you start in Outlook itself becomes a ticket with only your message; the ticket list filter Only Sent Messages finds such tickets; see Ticket lists.
• No history on connect. Replyco imports mail received from half an hour before its first sync onwards; older mail stays in Outlook.

What does not get imported

• Drafts.
• Junk Email.
• Mail outside the folders you chose, when you chose any, including mail in folders inside them.
• Mail received more than half an hour before the account’s first sync.
• Messages that are already in Replyco.

Outlook system messages without a sender arrive, but they cannot be answered from Replyco.

Setting it up in four steps

1. Open the Outlook tile. Select + Add Account in the top bar. The Add Account page opens; under Mailbox Accounts, select the Outlook tile. The dialog Authorize Replyco to sync with Outlook opens at AUTHORIZE.

   

   Outlook covers Microsoft 365 and Outlook.com mailboxes; it is the third tile under Mailbox Accounts.

   What this screenshot shows

   Screen

   Add Account (/integrations/add)

   Highlighted

   button “”, mailbox-tiles, enabled. opens the Outlook connect dialog

   Also visible

   Mailbox Accounts: Gmail, Email, Outlook; Order Management System Accounts below

   Purpose

   start connecting a Microsoft mailbox

2. Sign in with Microsoft. Select Authorize. Microsoft opens in a new browser tab; sign in with the account whose mailbox you want in Replyco and accept the permissions. The Replyco tab you started from shows Your Outlook account has been added successfully! already, but the account is saved only when Microsoft returns you; select Finish there.

3. Choose the folders (optional). Microsoft returns you to Replyco, which saves the account, shows Account successfully saved. and opens Almost done... with Set up Folders to Sync messages from. Pick folders in Sync Messages from Folders:, or leave the box empty to import every folder except junk, and select Finish. Replyco opens its start page.

4. Check that mail arrives. Open Admin›Accounts: the account appears with the mailbox address as its name and shows Syncing. Send a test message to the address from another mailbox and look for the ticket in your ticket lists within a few minutes.

Suggested rollout

Sign in once in a private browser window, so Microsoft asks which account to use instead of taking the one your browser is already signed in to. Connect with the folder choice empty, watch the first day of tickets, and only then narrow it to Inbox and the folders your Outlook rules fill.

On Microsoft’s sign-in pages

The Microsoft tab that Authorize opens has two pages (labels of Microsoft’s English interface):

1. Sign in. Enter the address of the mailbox you want in Replyco, select Next and sign in as your organisation requires, for example with the password and a second step.

   

   Sign in with the Microsoft account whose mailbox you want in Replyco.

   What this screenshot shows

   Screen

   ()

   Highlighted

   “”, , .

   Also visible

   Email address, phone number or Skype field; No account? Create one!; Can't access your account?; Back and Next buttons; Sign-in options

   Purpose

2. Accept the permissions. Microsoft lists what Replyco asks for: keep access to the data you give it, read your profile, read and write your mail, and send mail as you. Select Yes to accept them; Microsoft returns you to Replyco.

   

   Microsoft lists the permissions Replyco asks for; select Yes to accept them.

   What this screenshot shows

   Screen

   ()

   Highlighted

   “”, , .

   Also visible

   Maintain access to data you have given it access to; Read your profile; Read and write access to your emails; Send emails as you; No and Yes buttons

   Purpose

If your organisation lets only administrators approve apps, Microsoft asks for an administrator’s approval on the second page instead; see Troubleshooting.

Every setting, explained

The Outlook account has the Microsoft sign-in, the folder choice after Microsoft returns you, and the account’s details under Admin›Accounts, in the order below.

Microsoft sign-in, which mailbox Replyco connects

Where

The AUTHORIZE step of Authorize Replyco to sync with Outlook: Authorize opens Microsoft in a new browser tab. Later, Re-login in the account’s details opens it again.

What

Replyco connects the mailbox of the Microsoft account you sign in with. It names the account after the mailbox address, such as service@northwind-electronics.example.com, and sends replies with the name Microsoft has for the mailbox. A mailbox can be connected once: when an Outlook account with that name exists, Replyco refuses the new one with “Integration with this name already exists”. While Replyco saves the account, leaving the page asks Are you sure you want to leave this page? You have some unsaved changes. If you cancel on Microsoft’s page, nothing is saved and Replyco opens its start page.

Why

Signing in at Microsoft means Replyco never sees your password, and your organisation’s sign-in rules, such as two-factor authentication, keep applying.

Authorize opens Microsoft in a new tab; sign in there with the account whose mailbox you want in Replyco.

What this screenshot shows

Screen

Authorize Replyco to sync with {{name}} (/integrations/add)

Highlighted

button “Authorize”, dialog-bottom, enabled. opens Microsoft sign-in in a new tab

Also visible

step AUTHORIZE of two; text Add Outlook account to sync messages.; Need help? link

Purpose

send the user to Microsoft to allow access to the mailbox

Sync Messages from Folders:, which folders are imported

Where

First in Almost done... after Microsoft returns you, saved with Finish; the step is optional. Later in the account’s Account Details, saved with Save Changes. The box is marked BETA.

What

A list of the mailbox’s top-level folders, including folders Outlook hides, with the names the mailbox uses in its own language. Choose one or more; Select all ticks every folder and Deselect all clears them. With no folder chosen, Replyco imports every folder, the folders inside them included, except Junk Email and drafts; with folders chosen, only mail directly in those folders. A change applies from the next sync; mail already imported stays in Replyco.

Why

Sent Items, Deleted Items and Archive are full of mail that is not a customer question. Choosing folders, together with Outlook rules that move customer mail, keeps them out of your ticket lists.

Do	Don’t
Leave the box empty for a mailbox that only receives customer mail	Choose Select all: it adds Deleted Items and Archive
Choose Inbox plus the top-level folders your Outlook rules fill	Choose a folder whose customer mail sits in folders inside it
Keep customer folders at the top level of the mailbox	Expect a folder to keep working after you rename it in Outlook
Check the choice again after you reorganise folders in Outlook	Choose Sent Items unless you want mail sent from Outlook in Replyco

Choose the Outlook folders to sync, or leave the box empty to sync every folder except junk.

What this screenshot shows

Screen

Almost done... (/integrations/outlook/success)

Highlighted

combobox “Sync Messages from Folders:”, dialog, open. chooses the folders Replyco syncs

Also visible

heading Set up Folders to Sync messages from; list of top-level folders with Select all; Finish button

Purpose

choose which Outlook folders are synced

Change the synced folders at any time in the account's details, then select Save Changes.

What this screenshot shows

Screen

Account Details (/integrations)

Highlighted

combobox “Sync Messages from Folders:”, dialog, Inbox and Returns chosen. changes the synced folders; Save Changes stores them

Also visible

Account Name: service@northwind-electronics.example.com; Channel: Outlook; Receive Notifications about Blocking ticked; Delete Account, Save Changes

Purpose

change which Outlook folders are synced

Account Name:, the name your team sees

Where

The account’s Account Details, the first field. Saved with Save Changes.

What

Starts as the mailbox address. Change it to any name your team recognises; the new name is written onto the account’s existing tickets as well. Two Outlook accounts cannot share a name: Replyco refuses it with “Integration with this name already exists”.

Why

With several mailboxes connected, a name such as Northwind Service tells the team at a glance which mailbox a ticket came from.

Receive Notifications about Blocking

Where

The account’s Account Details, the check box above the folder box. Saved with Save Changes.

What

Ticked for every new Outlook account. While ticked, Replyco tells you by email and in the app when it blocks the account; cleared, no notice is sent.

Why

A blocked mailbox brings in no mail; the notice lets you sign in again before customers wait.

How the settings combine

Folder choice	Mail you send from Outlook itself	Mail in a folder inside Inbox
Nothing chosen	Imported as your team’s message	Imported
Inbox only	Not imported	Not imported
Inbox and Sent Items	Imported as your team’s message	Not imported
Your own top-level folders	Only if a rule moves it there	Not imported

Which should I choose?

Start with nothing chosen. Move to Inbox plus your own top-level folders once mail shows up in Replyco that does not belong there; it keeps customer mail and leaves sent, deleted and archived mail in Outlook.

Outlook in your tickets and your mailbox

What you do in Replyco on an Outlook ticket, and what it changes in the mailbox:

In Replyco	In Outlook
Send a reply	Sent from the mailbox as an answer in the customer’s conversation; it appears under Sent Items
Start a new email from Replyco	Sent from the mailbox as a new email; it appears under Sent Items
Open an unread ticket, or mark it read	Its messages are marked read
Mark a ticket unread	Its messages are marked unread
Archive, resolve, snooze, assign, label or set a priority	Nothing changes
Delete the Outlook account	Nothing changes; the mail stays in the mailbox

Tickets

Each Outlook conversation is one ticket. The customer is the sender of the message, or the reply-to address when the message names a different one. Attachments arrive with the message, and a reply the customer sends in the same conversation joins the same ticket. For every other part of the ticket, see The ticket screen.

Why: the ticket and the Outlook conversation stay one thing, so the history reads the same in both places.

Replies

A reply you send from the ticket goes out through Microsoft from the mailbox, as an answer to the customer’s message in the same conversation, and Outlook keeps it under Sent Items; the sender name is the one Microsoft has for the mailbox. Replyco sends exactly the text of its reply editor: the signature you keep for this account under Account Settings › Account Signatures is added there, the signature you set in Outlook is not. To set one up, see Account Signatures; for templates, attachments and sending, see Answer a ticket. If Microsoft does not accept a reply, the message shows Error Sending, and Try Again sends it again.

Why: the customer gets the answer in the conversation they started, from the address they wrote to.

Read and unread

Opening an unread ticket marks it read in Replyco and marks its messages read in Outlook; marking it unread does the reverse. A rule that marks messages as read does the same. Agents who keep Leave Tickets Unread switched on under Account Settings leave tickets unread when they open them; see Account Settings.

Why: a colleague working in Outlook sees what the team has already read in Replyco.

Archiving stays in Replyco

Archiving an Outlook ticket takes it out of your ticket lists but does not move anything in the mailbox. To tidy the mailbox as well, move the conversation in Outlook. For everything else about archiving, see Archived tickets.

The Accounts screen

The account appears on Admin›Accounts with the Outlook icon, the mailbox address as its name and the time of its last sync under Last Messages Sync. Select it to open its Account Details: the name, the folder choice, Receive Notifications about Blocking and Delete Account. For every column and button, see Accounts.

Why: the last sync time is the quickest check that the mailbox is still connected.

Reconnecting a blocked Outlook account

Where

Admin›Accounts: the account shows Blocked in red under Synchronization. Select it; the Account Details show Blocking reason: and the Re-login button.

What

Replyco renews its access to the mailbox by itself. It blocks the account when Microsoft refuses to renew it, for example after a password change, after the access was revoked in the Microsoft account or by your Microsoft 365 administrator, or when the mailbox is no longer active. The reason then reads “Your login token is expired, need relogin” followed by Microsoft’s own error, and a blocked account brings in no mail. Re-login opens Microsoft in a new tab; sign in with the same Microsoft account as before. Replyco connects the mailbox of whichever account you sign in with, so another account would bring in another mailbox. After you sign in, the block is lifted, the folder choice is kept, and the next sync catches up on the mail since the block.

Why

Microsoft’s access can end for reasons outside Replyco; signing in again restores it without losing the account, its tickets or its settings.

Three moments to use it:

• The account shows Blocked and the reason mentions an expired login token: select Re-login.
• You changed the password of the Microsoft account: expect the block, and sign in again as soon as the notice arrives.
• Your Microsoft 365 administrator reviewed app access: ask them to keep Replyco approved, then sign in again.

Re-login signs the mailbox in again; sign in with the same Microsoft account as before.

What this screenshot shows

Screen

Account Details (/integrations)

Highlighted

button “Re-login”, dialog-bottom, enabled. opens Microsoft sign-in for this account

Also visible

Blocking reason: Your login token is expired, need relogin; Last Messages Sync 06/03/2026 14:05:12; folders Inbox and Returns kept

Purpose

reconnect a blocked Outlook account

Your browser may choose the account for you

Microsoft often signs you in with the account your browser is already signed in to, without asking. If that is a different account, for example your personal one, Replyco connects that mailbox instead. Sign out of other Microsoft accounts first, or open Replyco in a private browser window, before you select Re-login. For blocks on other channels, see Fix a blocked or silent account.

What you need to know

Topic	Fact
Sync interval	About every five minutes; a new account is synced first.
History	None on connect: mail from half an hour before the first sync onwards.
One ticket per conversation	An Outlook conversation is one ticket; replies in it join the same ticket.
Folders	Top-level folders, chosen by name in the mailbox’s language; empty means every folder except Junk Email.
Folders inside folders	Imported only when nothing is chosen.
Mirrored to Outlook	Replies and read or unread. Archive, resolve, snooze, labels and priorities stay in Replyco.
Name and sender	The account is named after the mailbox address; the sender name comes from Microsoft.
Signatures	Replyco’s signatures for the account are used; the Outlook signature is not.
Shared mailboxes	Not connectable as an Outlook account; forward their mail instead.
Blocking	When Microsoft refuses to renew the access; Re-login with the same account lifts it.
Deleting	Deletes the account’s tickets, orders and customers in Replyco; nothing in the mailbox.
Access	Every user of the company gets the new account’s tickets; limit it under Users.
Plan	Every plan; counts against your plan’s number of accounts.

Frequently asked questions

General

Which Microsoft mailboxes can I connect?

Mailboxes of Microsoft 365 work or school accounts and of personal Outlook.com or Hotmail accounts, through the Outlook tile under Mailbox Accounts on the Add Account page. Replyco connects the mailbox of the account you sign in with; a mailbox on your own Exchange server cannot be connected this way.

Should I use the Outlook account or SMTP for a Microsoft mailbox?

Use the Outlook account. It signs in with Microsoft, needs no server settings and keeps working where Microsoft refuses passwords for SMTP. Connect other providers’ mailboxes over Mailbox with IMAP and SMTP; compare every way under Mailboxes.

Can I connect a shared Microsoft 365 mailbox?

Not as an Outlook account: the Outlook account connects the mailbox of the account you sign in with, and a shared mailbox has no sign-in of its own. Forward the shared mailbox’s mail to a Replyco address instead; see Mailbox by forwarding.

Does the Outlook account cost extra?

No. Outlook is part of every plan. Each Outlook account counts as one account against the number of accounts your plan allows, and when that number is reached, + Add Account no longer appears in the top bar until you remove an account or change your plan.

Setup

Who can connect an Outlook account?

Users with the Admin permission, because only they see the Admin menu with Admin›Accounts and + Add Account in the top bar. The person who signs in on Microsoft’s page needs the sign-in of the Microsoft account whose mailbox is connected.

Why can I not choose a name for the Outlook account?

Replyco names a new Outlook account after its mailbox address and takes the sender name from Microsoft. You can rename the account afterwards in Account Name: in its details under Admin›Accounts and select Save Changes.

Microsoft says the app needs an administrator’s approval. What now?

Your Microsoft 365 organisation lets only administrators approve apps. Ask your Microsoft 365 administrator to approve Replyco for the permissions it asks for, then select the Outlook tile under Mailbox Accounts again and sign in.

How much old mail does Replyco import when I connect Outlook?

None. Replyco imports mail received from half an hour before the account’s first sync onwards, so older conversations stay in Outlook. When a customer replies in one of them, the new message opens a ticket.

What does “Integration with this name already exists” mean when I connect Outlook?

An Outlook account with the mailbox address as its name already exists, usually because this mailbox is already connected. Use the existing account under Admin›Accounts; each mailbox needs only one Outlook account.

Folders

Which folders should I choose?

For a mailbox that only receives customer mail, choose none. For a mixed mailbox, use Outlook rules to move customer mail into top-level folders, then choose Inbox and those folders in Sync Messages from Folders: under Admin›Accounts and select Save Changes.

Why is a folder inside my Inbox not in the list?

The list shows the mailbox’s top-level folders only, and a chosen folder covers the mail directly in it. To import mail from a folder inside another folder, leave the choice empty, which imports every folder except Junk Email, or move that folder to the top level in Outlook.

Why do my own sent emails appear in Replyco?

With no folder chosen, Replyco imports every folder, Sent Items included, and mail sent from the mailbox arrives as your team’s message. To keep it out, choose Inbox and your own folders, without Sent Items, in Sync Messages from Folders: under Admin›Accounts.

I chose folders and now nothing arrives. Why?

Replyco imports only mail directly in the chosen folders. Check that your Outlook rules move customer mail into those folders and not into folders inside them, and that the names still match; a folder renamed in Outlook must be chosen again in the account’s details under Admin›Accounts.

Why are the folder names in German?

The list shows the folder names of the mailbox, and a mailbox set up in German calls its inbox Posteingang and its sent mail Gesendete Elemente. Choose the folders by the names your mailbox uses in Sync Messages from Folders:.

Replies and your mailbox

Do replies come from our own address?

Yes. A reply you send from an Outlook ticket goes out through Microsoft from the mailbox, as an answer in the customer’s conversation, with the sender name Microsoft has for the mailbox. Outlook keeps it under Sent Items like any email you send there.

Is our Outlook signature added to replies?

No. Replyco sends the text of its reply editor and adds the signature you keep for this account under Account Settings › Account Signatures. Copy your Outlook signature there; see Account Signatures.

Does archiving a ticket move the email in Outlook?

No. Archiving an Outlook ticket takes it out of your ticket lists in Replyco only; nothing moves in the mailbox. Opening a ticket and marking it read or unread, however, is mirrored: its messages are marked read or unread in Outlook.

Why is an email marked as read in Outlook although I did not open it there?

Someone opened the ticket in Replyco, or a rule marked it read. Opening an unread ticket marks its messages read in Outlook as well, unless the agent keeps Leave Tickets Unread switched on under Account Settings.

Why can I not reply to some Outlook messages?

Outlook system messages without a sender, such as some delivery reports, arrive as tickets but have no one to reply to, so Replyco offers no reply for them. Messages from a customer always carry a sender and can be answered.

Blocking and re-login

Why is my Outlook account blocked?

Microsoft refused to renew Replyco’s access, for example after a password change, after the access was revoked, or because the mailbox is no longer active. Open the account under Admin›Accounts, read Blocking reason: and select Re-login.

After re-login, Replyco shows mail from the wrong mailbox. What happened?

Microsoft signed you in with another account, usually the one your browser was already signed in to, and Replyco connected that mailbox. Sign out of every Microsoft account in the browser or use a private window, select Re-login again and sign in with the mailbox’s own account.

Do I lose mail while the account is blocked?

A blocked account imports nothing. After Re-login, the next sync catches up on the mail received since the block, so sign in again as soon as the blocking notice arrives. Keep Receive Notifications about Blocking ticked in the account’s details to receive it.

Data and privacy

What does Replyco store from our mailbox?

Replyco stores the Microsoft sign-in for the account, the mailbox address and the sender name, and the messages and attachments of the folders it syncs, as tickets. Junk Email and mail outside the chosen folders is not imported, and your Microsoft password never reaches Replyco.

What happens to our mail if we remove the Outlook account?

Deleting the account under Admin›Accounts deletes its tickets, orders and customers in Replyco after a confirmation, and cannot be undone. Nothing is deleted in the mailbox; the mail stays in Outlook. See Accounts.

Troubleshooting

Symptom	What to check
The Outlook tile is missing, or + Add Account is not in the top bar	You need the Admin permission. If you have it, your plan’s number of accounts is reached: delete an account or change your plan.
Microsoft asks for an administrator’s approval	Your Microsoft 365 organisation lets only administrators approve apps. Ask your administrator to approve Replyco, then connect again.
“Integration with this name already exists”	This mailbox is already connected. Use the existing account under Admin›Accounts.
You cancelled at Microsoft and no account was added	Nothing is saved until Microsoft returns you. Select the Outlook tile again and finish the sign-in.
No tickets arrive	In order: is the account Syncing? Does Last Messages Sync move? Is the mail directly in a chosen folder, not in a folder inside it? Did it arrive before the account’s first sync?
Old conversations are missing	Outlook imports no history. A customer’s next reply opens a ticket; answer earlier mail in Outlook.
Sent, deleted or archived mail becomes tickets	Nothing or Select all is chosen. Choose Inbox and your own folders.
Your own sent emails appear in tickets	Nothing or Sent Items is chosen. Choose Inbox and your own folders without Sent Items.
A shared mailbox cannot be connected	Shared mailboxes have no sign-in of their own. Forward their mail; see Mailbox by forwarding.
The account shows Blocked with “Your login token is expired, need relogin”	Select Re-login and sign in with the same Microsoft account.
After re-login, mail from another mailbox arrives	Microsoft used the account the browser was signed in to. Sign out of it or use a private window, then select Re-login again.
A reply shows Error Sending	Is the account blocked? Sign in again, then select Try Again on the message.
Replies carry no signature	Add one for this account under Account Settings › Account Signatures; the Outlook signature is not used.

Still stuck?

Contact Replyco support with the account’s name, the mailbox address, the text after Blocking reason: if there is one, and the time of a message that did not arrive. Support can see the account’s sync history and the folders it syncs.

Related

• Mailboxes
• Add Account
• Accounts
• Gmail
• Mailbox by forwarding
• Mailbox with IMAP and SMTP
• Fix a blocked or silent account
• Ticket lists
• Answer a ticket
• Account Signatures
• Specific Account Settings