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Cannot send via smtp.office365.com on TCP port 587

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  • Last reply by sfhowes

slyride
slyride
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Hi All,

I just added a second Office 365 account to my Thunderbird Profile. That broke the ability to send messages from either account. Thunderbird never sends an SMTP response after the server replies. I removed the second account, deleted both SMTP servers and then restarted Thunderbird and I was able to send again from the first account. I added the second account back, and once again, neither account is able to send. This time, I left the first account at smtp.office365.com and the second one at what it auto-discovered, smtp-mail.outlook.com. I tested this with 52.5.0 and with 58.0b2 (64-bit).

I think this is a bug of some kind, but maybe I'm missing something. Attached are a screenshot of the mail settings, and the packet capture.

Cheers,

Hi All, I just added a second Office 365 account to my Thunderbird Profile. That broke the ability to send messages from either account. Thunderbird never sends an SMTP response after the server replies. I removed the second account, deleted both SMTP servers and then restarted Thunderbird and I was able to send again from the first account. I added the second account back, and once again, neither account is able to send. This time, I left the first account at smtp.office365.com and the second one at what it auto-discovered, smtp-mail.outlook.com. I tested this with 52.5.0 and with 58.0b2 (64-bit). I think this is a bug of some kind, but maybe I'm missing something. Attached are a screenshot of the mail settings, and the packet capture. Cheers,

All Replies (1)

sfhowes
sfhowes
  • Top 25 Contributor
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Duplicate, continued at https://support.mozilla.org/en-US/questions/1195172