| Bill Jonas on Tue, 26 Feb 2002 00:35:33 -0500 |
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On Mon, Feb 25, 2002 at 10:07:01PM -0500, Doug Crompton wrote: > I was aware of that. I wonder if the reason I have never experienced this > is that my secondary MX is reverse DNS qualified. Does sendmail fail > entirely or drop to the secondary MX upon reverse DNS failure? I'm not aware of any SMTP servers looking up forward and reverse when sending mail *to* an MX server. What was referred to was when *your* server is sending mail to another one. Another example of improper reverse DNS causing breakage is the Debian default setting of /etc/hosts.deny, which is "ALL: PARANOID". tcpwrappers (and daemons which are linked against libwrap) will refuse connection from hosts for which forward and reverse do not match with this setting, although it should start with the reverse and then look up the forward based on what it gets back from the nameservers. (It doesn't have your hostname when you try to connect. SMTP is different because you tell it who you are in your HELO or EHLO command.) -- Bill Jonas * bill@billjonas.com * http://www.billjonas.com/ Developer/SysAdmin for hire! See http://www.billjonas.com/resume.html Attachment:
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