I looked around online to try to see examples to stop this but haven't found any yet. Maybe I'm missing something simple.
My postfix server does allow incoming connections from the outside world to deliver mail to mailboxes on my server which is what I want. And it does restrict relaying from outside networks to other email addresses and that's how I need it to work. It's great postfix is set to do this by default. However, an outside network can still identify as a local email account to send into my network, making imposters possible. Is there a flag I can use to stop this? Thank you for your help.
