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Can receive but not send emails and tried the help page hints already

Sirol
Sirol
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Hi, I just switched from Apple Mail to Thunderbird and I with both my providers (a University Server for work-mail and a mail provider from Germany for private messages) I can receive but not send messages. I tried everything on the "cannot send messages" page https://support.mozilla.org/en-US/kb/cannot-send-message, it does not work.

I am using Mac OSx Sierra on a 2012 Macbook. Thanks for your help!

Hi, I just switched from Apple Mail to Thunderbird and I with both my providers (a University Server for work-mail and a mail provider from Germany for private messages) I can receive but not send messages. I tried everything on the "cannot send messages" page https://support.mozilla.org/en-US/kb/cannot-send-message, it does not work. I am using Mac OSx Sierra on a 2012 Macbook. Thanks for your help!

Chosen solution

Those settings look good. It's rare that someone looking for help provides such useful info as you have with those screenshots. Awesome.

Cannot send mail has a bit more troubleshooting info.

Verify Thunderbird is in online mode, not offline mode: click "File -> Offline"; "Work Offline" should be unchecked.

Temporarily disable anti-virus & firewall and test sending.

Disable all Thunderbird add-ons, and test sending.

Beyond that, I am unable to help.

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All Replies (5)

user1121639
user1121639
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Did you verify the SMTP server settings with the e-mail providers? SSL or not SSL, port numbers?

Sirol
Sirol Question owner
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Hi, thanks for helping me, I really appreciate it. I did check the server settings, but I'll attach some screenshots for you.

user1121639
user1121639
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Chosen Solution

Those settings look good. It's rare that someone looking for help provides such useful info as you have with those screenshots. Awesome.

Cannot send mail has a bit more troubleshooting info.

Verify Thunderbird is in online mode, not offline mode: click "File -> Offline"; "Work Offline" should be unchecked.

Temporarily disable anti-virus & firewall and test sending.

Disable all Thunderbird add-ons, and test sending.

Beyond that, I am unable to help.

Sirol
Sirol Question owner
more options

Thanks Bruce, I think my problem is the Avast-Antivirus-Protection. I disabled it and now at least my Private Mailaccount works. Regarding my other Account I guess I'll just have to call the IT support at university. If you know any tricks regarding Avast and Thunderbird, I'll appreciate it!

user1121639
user1121639
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I am using Avast Pro Antivirus also, but am not having any problems with it and Thunderbird.

The article Antivirus software has some useful tips for using antivirus with Thunderbird.

The article Thunderbird:Testing:Antivirus Related Performance Issues has a section for Avast.

Avast Antivirus: Troubleshooting warnings about invalid mail server certificates when sending and receiving e-mails is also something that might help.