javersa

I know headers and email addresses can be forged, but is it possible that spammers are using my SMTP server? I see its IP address in the returned mail header. Are they set to require authentication to send for all email, or can someone post to the smtp using my domain and a false username?

I'm getting tons of returned mail for a few fake email addresses on my domain that spammers are using. I've found that if I create an account for the fake email addresses, I make sure they don't get forwarded to my default (and personal) email address and instead go to an inbox with a small quota.

Is there any better way to lock down the SMTP server? Or is even the ip address in the spammer's header faked?

Does this mean my domain is flagged in all kinds of spam blocking applications?

-Josh