Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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
Archyvinta

Help please

faxx

I'm suddenly unable to send emails. Error message reads "peer using unsupported version of security protocol" " The configuration related to mail @activ8.net.au must be corrected". This happened immediately after what appeared to be an update of Thunderbird. I have been into settings to try and rectify the problem without success.

I'm suddenly unable to send emails. Error message reads "peer using unsupported version of security protocol" " The configuration related to mail @activ8.net.au must be corrected". This happened immediately after what appeared to be an update of Thunderbird. I have been into settings to try and rectify the problem without success.

All Replies (5)

Same here. There seems to be a global problem after some change or update. So far no solution yet.

Thanks for the response Thomas. Hopefully the problem can be resolved without further delay or i will have to migrate to another server.









i

If you are using ESET/NOD32 security/AV then probability is very high it is causing your problems. According to their forums, you should temporarily disable SSL until they solve the problem per https://support.eset.com/en/kb3126-disable-ssl-filtering-in-eset-windows-products?ref=esf - the problem is being reported by dozens of users https://forum.eset.com/topic/26517-problems-with-thunderbird-and-imaps/ https://forum.eset.com/discover/

The 'unsupported protocol' error is caused by a conflict between the TLS on the mail server and the version required by TB:

https://support.mozilla.org/en-US/questions/1295861