Default filter rules prevent user-defined rules from being executed
Evolution 3.44.4-0ubuntu1 -> version might be old/outdated but I can think that the default rules are still in place (needs confirmation)
There are 3 default filters: "Personal, if only me", "Work, if I get mentioned" and "Non-personal if not to me". The first 2 default filters do contain "Stop Processing" as their last command.
For that reason, any user-defined rule that gets placed on the bottom (default behavior) is not executed as soon as one of the first two default rules are executed. The user might as well think that her filter rules are not working although they would work if the filter would be executed.
This is particular bad because users may create new rules from the context of an open email without knowing the "Message Filters" dialog and its default rules: Context of email list: "Create ...¨ > "Create filter rule for ...".
I'd recommend to mitigate this issue by one of:
- disabling default rules (no "Personal", "Work", or "Non-personal" labels any more),
- implementing a feature that user-defined rules are put above those default rules,
- an auto-popup of the "Message Filters" dialog after any new user-defined rule,
- default rules without "Stop Processing"
- alternatives I can't think of now
HTH