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

Èròjà atẹ̀lélànà yii ni a ti fi pamọ́ fọ́jọ́ pípẹ́. Jọ̀wọ́ béèrè ìbéèrè titun bí o bá nílò ìrànwọ́.

Can't send email - thunderbird

  • 2 àwọn èsì
  • 1 ní ìṣòro yìí
  • 3 views
  • Èsì tí ó kẹ́hìn lọ́wọ́ diegodad

more options

I installed Thunderbird on a new Windows 10 computer. When I try to send email I get this message: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) mail.twc.com was lost in the middle of the transaction. Try again. I verified with Spectrum that SMTP is correct using port 587. I tried turning off McAfee anti-virus and firewall.

I installed Thunderbird on a new Windows 10 computer. When I try to send email I get this message: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) mail.twc.com was lost in the middle of the transaction. Try again. I verified with Spectrum that SMTP is correct using port 587. I tried turning off McAfee anti-virus and firewall.

Ọ̀nà àbáyọ tí a yàn

Have you tried these settings? Outgoing server mail.twc.com on port 587 with Connection security = None, authentication = password, transmitted insecurely and User name = email address.

https://support.mozilla.org/en-US/questions/1161629

Ka ìdáhùn ni ìṣètò kíkà 👍 0

All Replies (2)

more options

Ọ̀nà àbáyọ Tí a Yàn

Have you tried these settings? Outgoing server mail.twc.com on port 587 with Connection security = None, authentication = password, transmitted insecurely and User name = email address.

https://support.mozilla.org/en-US/questions/1161629

more options

Thank you, sfhowes. I checked Connection Security on both my new laptop and an older desktop. The laptop is set to SSL/TLS while the desktop uses STARTTLS. I changes the laptop to STARTTLS and now the problem is gone.