Hi Carsten Thanks for your reply.
I'm considering this issue is normaly just of severity important. [...]
I agree.
As explained, I choose the higher one to make sure it triggers apt-listbugs. I was not aware that "a major effect on the usability" is not enough to trigger listbugs until now. I adjusted the config accordingly, but I assume a lot of users still have the default set.
But, using severity important would allow to migrate the package to > testing and more users would be affected by the issue.
The package already migrated to testing. That's why it hit me. $ aptitude versions thunderbird i 1:102.6.0-1 p 1:102.7.1-1 testing,unstable p 1:104.0~b2-1 experimental so listbugs is currently the remaining line of defence. best Nicola