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Thunderbird fails to gmail smtp - ssl_error_inappropriate_fallback_alert

  • 3 replies
  • 25 have this problem
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  • Last reply by jrpark22000

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I've a new install on an a work XP machine. The same install version on a home XP machine does not have the same problem with the same gmail accounts.

On the work machine with a clean install of 31.3.0 thunderbird, I cannot use gmail smtp services. Other smtp services to yahoo and my own domain work properly.

The error log; Timestamp: 1/7/2015 8:01:35 AM Error: An error occurred during a connection to smtp.googlemail.com:465. The server rejected the handshake because the client downgraded to a lower TLS version than the server supports. (Error code: ssl_error_inappropriate_fallback_alert)


Following the guide for a firefox issue I followed the recommendation to modify the "security.tls.version.min" https://support.mozilla.org/en-US/questions/1038836

For values 0 and 1, the same error log appears. For values 2 and 3 no error log is written to the error console yet sending mail still fails with; Sending of message failed. The message could not be sent using SMTP server smtp.googlemail.com for an unknown reason. Please verify that your SMTP server settings are correct and try again, or contact your network administrator

Any thoughts?

I've a new install on an a work XP machine. The same install version on a home XP machine does not have the same problem with the same gmail accounts. On the work machine with a clean install of 31.3.0 thunderbird, I cannot use gmail smtp services. Other smtp services to yahoo and my own domain work properly. The error log; Timestamp: 1/7/2015 8:01:35 AM Error: An error occurred during a connection to smtp.googlemail.com:465. The server rejected the handshake because the client downgraded to a lower TLS version than the server supports. (Error code: ssl_error_inappropriate_fallback_alert) Following the guide for a firefox issue I followed the recommendation to modify the "security.tls.version.min" https://support.mozilla.org/en-US/questions/1038836 For values 0 and 1, the same error log appears. For values 2 and 3 no error log is written to the error console yet sending mail still fails with; Sending of message failed. The message could not be sent using SMTP server smtp.googlemail.com for an unknown reason. Please verify that your SMTP server settings are correct and try again, or contact your network administrator Any thoughts?

Modified by jrpark22000

Chosen solution

If you use port 587, then set Connection Security to use STARTTLS.

In Thunderbird (not Firefox) 'config editor' check you have this:

  • security.tls.version.max; 3
  • security.tls.version.min; 1
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All Replies (3)

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On the same work machine I can add the gmail account into MS Outlook, sending to googlemail.com:465 or gmail.com:465 work properly.

Also tried switching Thunderbird to use ports 587 and 25. When using either of these ports thunderbird takes a minute, then fails to connect to the remote server. Error log get this written; Timestamp: 1/7/2015 8:34:31 AM Error: [Exception... "Component returned failure code: 0x8000ffff (NS_ERROR_UNEXPECTED) [nsIMsgMailNewsUrl.server]" nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)" location: "JS frame :: resource:///modules/activity/alertHook.js :: alertHook.onAlert :: line 48" data: no] Source File: resource:///modules/activity/alertHook.js Line: 48

I can't be certain if it is a corporate firewall issue or not. They may pinhole the ports when used by Outlook but block them from other apps.

Modified by jrpark22000

more options

Chosen Solution

If you use port 587, then set Connection Security to use STARTTLS.

In Thunderbird (not Firefox) 'config editor' check you have this:

  • security.tls.version.max; 3
  • security.tls.version.min; 1

Modified by Toad-Hall

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Thank you.

Verified these are current values In Thunderbird (not Firefox) 'config editor' check you have this: security.tls.version.max; 3 security.tls.version.min; 1

The fix was too easy. I'm up and running. "If you use port 587, then set Connection Security to use STARTTLS."

Modified by jrpark22000