Unable to Access Outlook Mail Account With Mailbird

Question

Setting up Outlook in Mailbird I get and error: 'An error occurred authorizing Mailbird to access the mail account.

INCOMING
Microsoft OAuth 2.0
IMAP
outlook.office365.comSSL/TLs
SMTP
smtp.office365.com

Anything I need to change? <Mod removed PII>

Answer 1

Hi James,

I understand how frustrating it is to see “An error occurred authorizing Mailbird to access the mail account” during setup. Since this happens at the authorization stage, it is usually not caused by the port numbers themselves, but rather by the account’s IMAP/POP access setting or the sign‑in method being used.

Please try the following checks:

1, Confirm IMAP access is enabled in Outlook.com:

Sign in to Outlook.com on the web, go to Settings, then locate the section for Mail sync settings (often shown under Mail > Sync email / Forwarding and IMAP). Make sure IMAP is allowed for the account and save the change.

Mailbird also documents this same symptom and points to enabling IMAP/POP in Outlook.com settings as the key fix: https://support.getmailbird.com/hc/en-us/articles/28233227303831-An-error-occurred-authorizing-Mailbird-to-access-a-Microsoft-email-account

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2, Re-add the account in Mailbird and complete the OAuth sign-in flow

After confirming IMAP is enabled, remove the account from Mailbird and add it again, ensuring “Microsoft OAuth 2.0” (or OAuth2) is used. Microsoft has moved away from basic sign-in for many third‑party mail apps, so the sign‑in experience should go through the modern authentication prompt.

3, Double-check the server settings match the type of account you’re adding

Microsoft publishes the correct POP/IMAP/SMTP settings and notes that values can differ depending on whether the mailbox is Outlook.com (personal) or Microsoft 365 (work/school). Use the official settings listed here to verify your incoming and outgoing server entries: POP, IMAP, and SMTP settings for Outlook.com - Microsoft Support

If the same authorization message continues even after IMAP is enabled and the account is re-added using OAuth, the next step would be to work with Mailbird support, since the authorization window and token handling are controlled by the third‑party app.

I hope this helps narrow down the cause and gets the account added successfully. 

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