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POP3 Connection to MS365

itsupport17
itsupport17
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I am having a problem receiving messages today in my Thunderbird email account from MS365. The message reads - The RETR command did not succeed. Error retrieving a message. Mail server outlook.office365.com responded: Server Unavailabble. 21

I did delete all messages from all my folders in the email account to see if it was a particular message that was stuck. My email account has 5GB of empty space currently. Did Microsoft make some changes? Any solutions

Maria

I am having a problem receiving messages today in my Thunderbird email account from MS365. The message reads - The RETR command did not succeed. Error retrieving a message. Mail server outlook.office365.com responded: Server Unavailabble. 21 I did delete all messages from all my folders in the email account to see if it was a particular message that was stuck. My email account has 5GB of empty space currently. Did Microsoft make some changes? Any solutions Maria

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wirkutskijkarl
wirkutskijkarl
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I ran into the same issue today with Thunderbird and my Office 365 account — exact same RETR error. It looks like it might be a temporary issue on Microsoft's side. I checked the Office 365 service status page and there was a mention of intermittent mail delivery issues earlier.

In the meantime, try switching from POP to IMAP if you're still using POP3 — that might help bypass the RETR command altogether. Also, restarting Thunderbird in Safe Mode (Help > Troubleshoot Mode) helped me rule out add-on issues.

Let’s hope Microsoft resolves it soon if it’s on their end!

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