Been running Mailcow for a few years now, love not being beholden to MS/Google!
To the issue, my company has a web app where we deal with user tickets, Mailcow is used for our general company inbox and for staff. We get users emailing either staff or the general inbox, when they should be using the ticket system or they do both. Is is possible to create a filter based on email addresses within our web app database? So, if a user who is registered in our web app, tries to email an inbox on the Mailcow server, they would get a reject message?
Thanks in advance for any ideas, suggestions!