In article <mailman.737.1372773227.20661.bind-us...@lists.isc.org>, Daniel McDonald <dan.mcdon...@austinenergy.com> wrote:
> The other place reverse DNS is routinely queried is SMTP. If you care > enough to send mail, you should care enough to set up your reverse entries > realistically so that spam filters will recognize that you are trying to > actively manage your email server and this isn't mail from a BOT... Reverse DNS is generally necessary, but may not be sufficient. Your IP also has to NOT be on one of the many block lists. These lists are populated with IPs that have spamming history, as well as IPs that ISPs have volunteered as being used for residential services rather than commercial users. I suppose it's obvious, but the other general place where reverse DNS is important is if you make use of hostnames or domain suffixes in filter files like hosts.allow and hosts.deny. If your hosts.allow file contains something like: sshd: *.yourdomain.com then the server will do a reverse lookup and forward validity check before testing whether the hostname ends in .yourdomain.com. -- Barry Margolin Arlington, MA _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
