Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Since loading Thunderbird 60, I cannot send email; receive is fine, but sending I get error message that transmission failed.

  • 3 cavab
  • 1 has this problem
  • 1 view
  • Last reply by Gulliver6

more options

I can receive mail fine, but I cannot send. I have verified with my ISP the smtp settings and re-installed Thunderbird. But it still fails with:

Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.redshift.com was lost in the middle of the transaction. Try again.

Nothing has changed besides the new vsn of Thunderbird. I have included a screen shot of the smtp settings.

Thanks for any insight.

I can receive mail fine, but I cannot send. I have verified with my ISP the smtp settings and re-installed Thunderbird. But it still fails with: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.redshift.com was lost in the middle of the transaction. Try again. Nothing has changed besides the new vsn of Thunderbird. I have included a screen shot of the smtp settings. Thanks for any insight.
Attached screenshots

Chosen solution

One document suggests using smtp.redshift.net on port 465, SSL/TLS security, while another suggests smtp.redshift.net on port 587, STARTTLS security, authentication = encrypted password.

See if changing the security to SSL/TLS on port 465 makes any difference. Servers that require encrypted password authentication are fairly uncommon.

The TB update may have conflicted with your firewall/antivirus program if they're not the built-in W10 ones.

Read this answer in context 👍 1

All Replies (3)

more options

Seçilmiş Həll

One document suggests using smtp.redshift.net on port 465, SSL/TLS security, while another suggests smtp.redshift.net on port 587, STARTTLS security, authentication = encrypted password.

See if changing the security to SSL/TLS on port 465 makes any difference. Servers that require encrypted password authentication are fairly uncommon.

The TB update may have conflicted with your firewall/antivirus program if they're not the built-in W10 ones.

more options

Turns out my ISP has supplied me with the correct port number and protocol, but somehow in the re installation I had saved an incorrect password for the smtp server. So minor surgery for shooting myself in the foot and thanks for your input.

more options

I have a similar problem. It seems that Thunderbird automatically reverts all settings in the Send-Mail pane to their standards with every major new release of the app. Very annoying!