Logic of "Do not sign meeting requests" is inverted.
If I configure Evolution in the way to sign all outgoing messages and if I set the option to not sign meeting requests, they will be signed anyway. Furthermore they will not signed, if I uncheck the option to not sign meeting requests.
I think, the problem could be here: https://gitlab.gnome.org/GNOME/evolution/-/blob/master/src/composer/e-msg-composer.c#L1961
The method should be named "e_source_mail_composition_get_not_sign_imip" as the option label states. Therefore, the logic is inverted here.
Here the method seems to be used correctly (despite the wrong name).
Edited by Michael Neuendorf