Bob Goodwin - W2BOD wrote: > Mikkel L. Ellertson wrote: >> Have you looked in /var/log/maillog for an error message? It is >> possible in the changes you mentioned, your ISP now requires >> authentication before accepting mail. Another possibility is that >> your ISP now requires that the there be a reverse DNS for the >> hostname of the mail server that is sending it a message. >> >> Mikkel >> > "reverse DNS?" Wireshark displayed a number of lines about DNS which I > did not understand. I hate to admit it but what's a reverse DNS? Guess > I need to look that up ... > > Bob Goodwin > That is where they take your IP address, and look up the hostname that goes with it. There is an option to reject mail if they do not match. It is not usually a good rule to use. Another check that is sometime done is to check for a MX record for the domain the message is coming from. It stops mail from fake domains. But not all domains have a MX record... Mikkel -- Do not meddle in the affairs of dragons, for thou art crunchy and taste good with Ketchup!
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