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

Unable to send emails from Thunderbird

  • 1 reply
  • 1 has this problem
  • 13 views
  • Paskiausią atsakymą parašė sfhowes

more options

Hello, tech support. I am trying to set up Thunderbird as an email client to support my new email account with StartMail and am having trouble sending emails from Thunderbird. Receiving is just fine. I requested a trusted IMAP device through StartMail, and it gave me recommended server settings and a password. The SMTP server setting they wanted was 465, TLS, normal password, smtp.startmail.com.

When I tried to set that up by adding an account on Thunderbird, Thunderbird's recommended server settings were 587, STARTTLS, normal password. When I tried to manually change the settings to StartMail’s recommendations, it would not allow me to save them.

I don’t know if I should be trying to “add another account”. When checking the server settings for my username@startmail.com, the IMAP is set at SSL/TLS, normal, port 993 (all OK), and the SMTP is set at SSL/TLS, normal, 465, smtp.startmail.com (just like Startmail wants). Regardless – I can’t sent emails out from Thunderbird.

When trying to send an email from Thunderbird, the error messages say “Logon to account with username… failed” and “sending of message failed – unable to authenticate to outgoing SMTP server – please check password or verify authentication method in Account Settings/outgoing server SMTP”

I’m not that tech savvy, so if you could provide an answer with step by step instructions, that would be very helpful. Thanks.

Hello, tech support. I am trying to set up Thunderbird as an email client to support my new email account with StartMail and am having trouble sending emails from Thunderbird. Receiving is just fine. I requested a trusted IMAP device through StartMail, and it gave me recommended server settings and a password. The SMTP server setting they wanted was 465, TLS, normal password, smtp.startmail.com. When I tried to set that up by adding an account on Thunderbird, Thunderbird's recommended server settings were 587, STARTTLS, normal password. When I tried to manually change the settings to StartMail’s recommendations, it would not allow me to save them. I don’t know if I should be trying to “add another account”. When checking the server settings for my username@startmail.com, the IMAP is set at SSL/TLS, normal, port 993 (all OK), and the SMTP is set at SSL/TLS, normal, 465, smtp.startmail.com (just like Startmail wants). Regardless – I can’t sent emails out from Thunderbird. When trying to send an email from Thunderbird, the error messages say “Logon to account with username… failed” and “sending of message failed – unable to authenticate to outgoing SMTP server – please check password or verify authentication method in Account Settings/outgoing server SMTP” I’m not that tech savvy, so if you could provide an answer with step by step instructions, that would be very helpful. Thanks.

All Replies (1)

more options

Use imap.startmail.com on 993, SSL/TLS and smtp.startmail.com on 465, SSL/TLS; authentication = normal password, User Name = email address.

https://support.startmail.com/hc/en-us/articles/360006596718-Server-addresses

If you already have the servers entered in TB, for the smtp, change the security to SSL/TLS and the port should change automatically to 465. Sending on port 587 would normally be with STARTTLS security.

What is the antivirus? Some of them can interfere with sending if they are set to scan outgoing mail. A VPN, if you have one, is another potential blocker.