Ok, thanks very much Rolf.  I'll revert to clients tech support with your findings.

Ron

Hi,

I've got a strange one. Not sure it has anything to do with MercE, but just to be sure:

MercuryE (v4.72) gives me the following error message trying to deliver e-mail to the domain (I'm reluctant to give the actual domain name, it's one of our clients).

 ------------------------------------------------------------------
*** address@clientdomain.com
Permanent error 11001 (non-existent host or domain) resolving clientdomain.com'.
-------------------------------------------------------------------

Session logging shows the same error. Normally pretty clear, dns issue or the domain actually doesn't exist. But running nslookup for clientdomain.com on the server Merc/32 runs on, resolves and returns the correct MX record without any problem. I double checked, MercE uses the same DNS servers as the Windows box it runs on. Sending a test e-mail to exactly the same e-mail address from my private ISP's SMTP server, no problem. The e-mail gets delivered. Client's tech support tells me their servers are up and running without any problems. 

The real domain name is lengthly, 22 characters. That's the only thing I can think of right now. Could there be a bug in MercE with rather long domain names?

Thanks, Ron

If you send me a private message (click on my name, then on Private message) with the real rejection data I can have a look at it.

/Rolf

MercuryE (v4.72) gives me the following error message trying to deliver

e-mail to the domain (I'm reluctant to give the actual domain name,

it's one of our clients).

Without the domain name we can do nothing to help you.  FWIW, I've sent to domains much longer than 22 characters without any problem and so I suspect that the problem is one where the DNS is not properly resolving the domain.  FWIW, providing the domain name is not any sort of security problem.

That said, you might want to try using the OpenDNS servers in the MercuryE setup so as to preclude any local DNS problem.

Hi Rolf,

I've sent you the PM with the real domain name and the nslookup results of the Windows box Merc/32 is running from.

Thanks

Ron

OK, got it. I made a nslookup as well (data partially masked):

 Name=xxxxxxxxxxxxx.com
    Type=MX, Class=1, TTL=86400 (1 Day), RDLENGTH=18
    Preference=10, Mail Exchange=xxx.xxx.108.250

The problem is that a MX record must contain a hostname (A record), numerical IP addresses are not allowed. Some mail servers are more lenient regarding this, but it's a strict RFC requirement and Mercury will not allow it.

The fallback if there is no (correct) MX is to try to send to the IP address assigned to the domain itself. In this case there is no such address, so that's the reason for the wording in the error message.

/Rolf