I have a customer with website and their contact us form's mail seems to be blocked by postfix. I'm seeing the following delayed mail in the mailqueue: There are around 20 of them. I have an alias setup for [email protected] for the customers domain, which forwards to a mailbox on their domain but since I saw this issue, I disabled it and created a webmaster mailbox, but still mail was not being accepted. The form collects the users email via an input box and uses that input as the from address in the email (at least that is what is how the mail is addressed by the php of the web page). I did suspect that the blocked emails might be due to the customer testing their contact us form and putting "[email protected]" for the email address, rather than their own actual email, however, I tried their form myself and grepped the mail.log for my email address and didn't find it, so is it possible that [email protected] is being set by the .vhost file? This is what we're seeing in the mail.log: Any thoughts on this would be greatly appreciated!