We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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

Authentication failure with SMTP-server

  • 10 tontu
  • 3 am na jafe-jafe bii
  • 1 view
  • i mujjee tontu mooy kompak

more options

I've been running Thunderbird for years on Gentoo which has version 115.10.1 as the most recent. I don't send much mail so I'm not exactly sure when this problem occurred, but I'm unable to authenticate with my SMTP server. I have not changed any configuration. Some weeks ago a changed my password on the server, but I made the appropriate changes to Thunderbird password manager. All settings, username and passwords are 100% correct as I copy pasted all of them. IMAP on the same server (uses same credentials) works.

I have tried deleting and re-adding my accounts which did not help. I have also tried deleting my profile folder. All other mail clients (e.g. claws-mail, kmail, mailspring) with the same SMTP server don't have any problems sending mail. This problem seems to only affect Thunderbird and Thunderbird forks such as Betterbird.

I have no firewall and am using SSL authentication with cleartext password on the SMTP server.

I get the following output to console on attempted sending of message:

console.error: (new Error("Server error 503 Service Unavailable", "resource://services-settings/Utils.sys.mjs", 390)) console.error: mailnews.smtp: "Command failed: 535 Incorrect authentication data; currentAction=_actionAUTHComplete" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.send: "Sending failed; Unable to authenticate to Outgoing server (SMTP) mail.kapsi.fi. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'., exitCode=2153066805, originalMsgURI="

I've been running Thunderbird for years on Gentoo which has version 115.10.1 as the most recent. I don't send much mail so I'm not exactly sure when this problem occurred, but I'm unable to authenticate with my SMTP server. I have not changed any configuration. Some weeks ago a changed my password on the server, but I made the appropriate changes to Thunderbird password manager. All settings, username and passwords are 100% correct as I copy pasted all of them. IMAP on the same server (uses same credentials) works. I have tried deleting and re-adding my accounts which did not help. I have also tried deleting my profile folder. All other mail clients (e.g. claws-mail, kmail, mailspring) with the same SMTP server don't have any problems sending mail. This problem seems to only affect Thunderbird and Thunderbird forks such as Betterbird. I have no firewall and am using SSL authentication with cleartext password on the SMTP server. I get the following output to console on attempted sending of message: console.error: (new Error("Server error 503 Service Unavailable", "resource://services-settings/Utils.sys.mjs", 390)) console.error: mailnews.smtp: "Command failed: 535 Incorrect authentication data; currentAction=_actionAUTHComplete" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.send: "Sending failed; Unable to authenticate to Outgoing server (SMTP) mail.kapsi.fi. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'., exitCode=2153066805, originalMsgURI="

Saafara biñ tànn

I finally found the solution to this problem. Thunderbird seems to be not able to send passwords with non ASCII characters properly to SMTP-servers. Strangely this only is the case with SMTP. IMAP passwords can contain non ASCII characters.

This bug is marked resolved, but apparently it is not.

Jàng tontu lii ci fi mu bokk 👍 0

All Replies (10)

more options

Maybe if you post a screenshot of your smtp settings, it will present a more complete picture of your issue. Thank you.

more options

Of course here it is. These settings work perfectly fine in any other email client except Thunderbird.

more options

Are you including your full email id or just the prefix before the @?

more options

Just my username.

more options

Please try with full email address.

more options

It won't work as I have a specific username for the server.

more options

You mentioned that you changed settings to password manager. How was that done? My suggestion would have been to go to settings>privacy&security and delete both entries for the account and let Thunderbird then prompt for password.

more options

david said

You mentioned that you changed settings to password manager. How was that done? My suggestion would have been to go to settings>privacy&security and delete both entries for the account and let Thunderbird then prompt for password.

That is exactly what I tried first. Since then I have tried complete deleting all accounts and even deleting my whole profile folder.

more options

Ok, I'm lost. My only other thought would be whether you have more than one account, as that could be the issue if they're using the wrong smtp server. Do you get the same error when you use the full email address?

more options

Saafara yiñ Tànn

I finally found the solution to this problem. Thunderbird seems to be not able to send passwords with non ASCII characters properly to SMTP-servers. Strangely this only is the case with SMTP. IMAP passwords can contain non ASCII characters.

This bug is marked resolved, but apparently it is not.