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IMAP ok but SMTP fails on Windows 11

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Plortus
Plortus
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Hello,

I have been using Thunderbird for many years without any issues. I recently bought a laptop running Windows 11. On this machine, I have two accounts that cannot send emails via SMTP. What is puzzling is that I can retrieve emails through IMAP without any problems.

For another account I had to use STARTTLS to get it working. But on my Windows 10 machine, the same account is sending emails correctly with SSL/TLS.

Thunderbird is allowed through the Windows firewall and is on the antivirus whitelist.

I recently fixed an issue (connecting to Gmail) by allowing cookies, so it might be a simple fix like that.

Could someone help me, please?

Many thanks!

Hello, I have been using Thunderbird for many years without any issues. I recently bought a laptop running Windows 11. On this machine, I have two accounts that cannot send emails via SMTP. What is puzzling is that I can retrieve emails through IMAP without any problems. For another account I had to use STARTTLS to get it working. But on my Windows 10 machine, the same account is sending emails correctly with SSL/TLS. Thunderbird is allowed through the Windows firewall and is on the antivirus whitelist. I recently fixed an issue (connecting to Gmail) by allowing cookies, so it might be a simple fix like that. Could someone help me, please? Many thanks!
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Hello Matt,

Thank you for your answer.

I installed and wiped all data to start with a fresh new installation. It didn't solved my issue, but I understood why: I think that the network at my working place that is filtering the access to some email providers! I juste can't understand why I can get emails but not send them...

My Thunderbird installation works perfectly fine at home but not at my working place.

Have a nice day.

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Matt
Matt
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Please verify you do not have an antivirus scanning outgoing mail.

Clearly based on your comments you are not running a default installation, or cookies would be allowed automatically. So if you are having issues, returning things to their defaults would be a good start.

Plortus
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Vald lösning

Hello Matt,

Thank you for your answer.

I installed and wiped all data to start with a fresh new installation. It didn't solved my issue, but I understood why: I think that the network at my working place that is filtering the access to some email providers! I juste can't understand why I can get emails but not send them...

My Thunderbird installation works perfectly fine at home but not at my working place.

Have a nice day.