I am not sure if it is just me or anyone else has seen this. I am running the latest macOS (10.14), latest MailMate (1.12) and latest SpamSieve (2.9.33).
After upgrading the OS and everything, when I open MailMate (my MUA of choice) it automatically runs SpamSieve upon arrival of new mail (as intended). Now the weird thing is, a second passes after SpamSieve is launched and Mail.app also launches automatically. This is really annoying and I tried reinstalling the SpamSieve and going through all configuration options, but I couldn’t see what is wrong and what is triggering Mail.app to run.
If anyone else is experiencing similar issue, please share your experiences. Your suggestions are very welcome to eliminate this annoying issue.