But these emails ultimately do get sent out. It could take a long time. To me it sounds odd that they don't know their DNS lookups are screwed up. And if they do know, why are they placing such strict constraints on incoming mail. From: Peter Sent: 9/1/2013 8:32 PM To: postfix-users@postfix.org Subject: Re: ISP has no reverse DNS for ip address On 09/02/2013 12:11 PM, Noel Jones wrote: > On 9/1/2013 6:57 PM, Roman Gelfand wrote: >> On every machine, at different locations, I have tried "dig -x ip >> address" and it works correctly. >> >> I have 4 messages stuck in a queue which are complaining about the >> very thing that works. >> >> refused to talk to me: 451 Sender's ISP has no reverse DNS for ip address >> >> Can somebody tell me what is going on? > > It appears the recipient is unable to find your rDNS. You might > check your setup with some external tools, or maybe the recipient's > DNS is broken. > > Or the reason given could be incorrect, and they don't want your > mail for some other reason. If your DNS looks OK, you'll need to > contact their postmaster.
A lot of times the complaint is about RDNS when they really mean FCRDNS. Check that forward records match as well before you go off complaining to the other postmaster. Peter
