On 01/09/12 1:30 PM, Ljubomir Ljubojevic wrote: > I own my own domain/server/subnet. My WISP customers can only send mail > via my server, with all the prevention's I could think of. I have never > been hit with this (but I do have small customer base), but I have had > regular domains (like one local Bank!!!) blocked to deliver to my server > because they do not have proper FQDN. I too run a few mail servers... none of my servers will accept incoming email from a host that doesn't have a reverse DNS that when looked up returns the original IP (eg, IP -> reverse -> forward -> IP... note this doesn't have to match the HELO name). I also check that the 'from' domain name has an A or MX record. This sort of thing has been standard practice for email servers for at least 15 years. The way I figure it, if someone can't get the DNS right, they shouldn't be running a email server at all. -- john r pierce N 37, W 122 santa cruz ca mid-left coast