Mac Server - Postfix Issue on certain ISP or Network

[rjbathgate]

Hi,

I have Mac Server and MAMP running as my local server, and have set up Postfix in MAMP to enable outgoing mail.

I have the smart host set as gmail.com

When I connect the machine to the internet using my mobile phone network (vodafone), all works perfectly.

However, when I connect the machine to the internet with my normal ISP, through my LAN, postfix returns the error:

Host or Domain name not found. Name service error for name=gmail.com type=MX Host not found, try again

I have tried it changing the smarthost to the ISP's mail.isp.com, same issue.

Using the command dig gmail.com (or indeed dig myisp.com) it ONLY returns A names, no MX. A 'dig gmail.com MX' (or dig myisp.com MX) returns a timeout.

My LAN is a router behind a modem, nothing more than that.

So, where should I start?

The fact it works on my vodafone ISP suggests it's either an issue with my normal ISP blocking something? or my local network set up?

Any suggestions, most appreciated.

Thanks

[falko]

I think you should try other nameservers, e.g. the ones from Google:
8.8.8.8
8.8.4.4

[rjbathgate]

Thanks for the reply.

My /etc/resolv.conf looks like this:

nameserver 8.8.8.8
nameserver 8.8.4.4

however the same problem exists - mail send fails with same error.

However now dig mydomain.com MX is returning MX records instead of timing out...

But mailq returns "name service error for name=gmail.com type=MX: host not found, try again"

If I change domain of outgoing in MAMP Postfix to imap.gmail.com, same error.

So we've got somewhere in that it can return dig MX now...

Thanks again in advance.

Cheers