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Thunderbird Cannot Send Email Through Outlook Account

  • 4 replies
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  • 1 view
  • Last reply by tjcorcoran

tjcorcoran
tjcorcoran
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I installed Thunderbird 115.0.1 on Windows 11. I configured it for two accounts. One was a custom domain managed by Google, the second an Outlook account with my Office365 subscription.

Both receive mail fine. Neither would send mail. Investigating further I found that Thunderbird never got a firewall exception. I added the exception and now the Google account sends and receives fine. Outlook will still not send.

I've removed and re-added the Outlook account a couple of times now. No joy. I have found a lot of conflicting information on SMTP server settings but currently have the queried (auto configured) smtp.office365.com server on port 587 with my account credentials for login, connection security of 'STARTTLS' and authentication method of 'normal password'.

I've tried a couple of other email clients and they work out of the box. Any help would be appreciated.

-T

I installed Thunderbird 115.0.1 on Windows 11. I configured it for two accounts. One was a custom domain managed by Google, the second an Outlook account with my Office365 subscription. Both receive mail fine. Neither would send mail. Investigating further I found that Thunderbird never got a firewall exception. I added the exception and now the Google account sends and receives fine. Outlook will still not send. I've removed and re-added the Outlook account a couple of times now. No joy. I have found a lot of conflicting information on SMTP server settings but currently have the queried (auto configured) smtp.office365.com server on port 587 with my account credentials for login, connection security of 'STARTTLS' and authentication method of 'normal password'. I've tried a couple of other email clients and they work out of the box. Any help would be appreciated. -T

Chosen solution

The outgoing server is smtp.office365.com, 587, STARTTLS, OAuth2 authentication, User Name = email address.

https://support.mozilla.org/en-US/questions/1417298#answer-1588949

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All Replies (4)

david
david
  • Top 10 Contributor
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My smtp server is outlook.office365.com

tjcorcoran
tjcorcoran Question owner
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Tried that. Still doesn't work. I practiced my google-fu and found Microsoft's published settings:

SMTP Server Server Name: smtp-mail.outlook.com Port: 587 Connection Security: STARTTLS

It also says no encrypted authentication required, so I left it (after trying all of them) on 'Normal Password'.

I finally find a client I like and now this! ;P

-T

sfhowes
sfhowes
  • Top 10 Contributor
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Chosen Solution

The outgoing server is smtp.office365.com, 587, STARTTLS, OAuth2 authentication, User Name = email address.

https://support.mozilla.org/en-US/questions/1417298#answer-1588949

tjcorcoran
tjcorcoran Question owner
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Success! Combination was off. Thank you @sfhowes