2009/3/13 Marc Jauvin <m...@r4l.com>: > Since we have no means to know that the MX records were modified, then we > can't "remove" those virtual mapping rules from our database.
As others have said, you need to make sure your postfix configuration matches the reality of the situation. As I work at a webhosting company I can understand this problem, it happens every now and then. If cross-checking against DNS is too hard you may consider a change to how you send your mail. Send your "outgoing" mail to customers via a separate MX that queries authoritative DNS, and doesn't host mail for any domains. Of course you still need to be careful there; if you host DNS for the customer, but they delegate the domain to another DNS provider without telling you, you could still end up sending mail to your own mail servers incorrectly. If this is a possibility, you need to make REALLY sure you only host DNS for domains which are delegated to you, or find a way to do DNS lookups outside your own network.
