jorgk3

Thanks for your help, but you didn't answer this question: Is there any way to configure ZNC to pretend not to support echo-message? So I don't trigger the TB bug?

Thanks for considering it. Since "my" ZNC is running on some Debian system, it will be a while a new version would come into effect.

FYI, Thunderbird fixed the echo-message issue. (I'm sure you noticed since you're following the bug.)