How Configure Postfix to allow send emails only for existing email address


How can I configure this on virtualmin?

This can reduce sending spam from hacked sites...

thank you



Howdy -- that unfortunately may not be to easy, as you'd need to maintain a list of users who can send email.

It's also a bit of an advanced Postfix setup that we don't have much experience testing.

However, if you're interested in trying that, there's a couple of different ideas you might try.

This here might do what you're after:

This is also another example of what might work: