I have several machined behind a firewall with no external visibility, relaying mail through an external machine. When the mail reaches destination machines that require a revDNS lookup to process the mail it tries to revlookup the hostname and fails. I am planning on installing the lates Sendmail w/ M4 on all the machines (solaris), Can anyone offer any assistance?
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Rev DNS faliure for Sendmail machine behind firewall
- Thread starter kdbenner
- Start date
If you're wanting to fix the reverse problem, you just need to have your ISP add a reverse lookup for the IP the external mail servers see. I would expect that the external mail server sees the IP of your firewall so this would be the IP they need to add a reverse for. You will just need to send them a request to add a reverse for your mail server's host name and the IP seen from the outside.
If you have a full Class C network, you can manage the reverses yourself but if not, your ISP is the only one who can setup and manage the reverse lookups.
Good luck and let me know if you have any other questions,
GJ
If you have a full Class C network, you can manage the reverses yourself but if not, your ISP is the only one who can setup and manage the reverse lookups.
Good luck and let me know if you have any other questions,
GJ
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