Hello and thank you for your reply. I double-checked the filters with:
It returned nothing. I checked manually by scrolling through the output of zmprov ga firstname.lastname@example.org and indeed the property is not there. I assure you there is nobody else using my account (POP or otherwise) and I am using no other email clients.
zmprov ga email@example.com | grep zimbraMailSieveScript
If you have specific logs in mind that I can grep for output please let me know and I can provide more info here.