I am currently using SME Server version 7.5.1 and using Qmail as the MTA. I have absolutely no issues w/ sending or receiving emails at all, but only with one domain which is intermedia.net (Microsoft Exchange Hosting Company). One of our contractors which is cardinalco.com which is hosted by intermedia.net cannot send email to us nor can we send to them. I have looked at everything I can think of such as the mx record, reverse dns, firewall, blah blah blah blah and I cannot figure this out. I opened up a ticket with Intermedia and they snobbishly said its not our issue. Kind of funny I have had this server up for years and we speak to several contacts within the US and abroad no issues but only with Intermedia.net. Anyways if I try to send them an email here is the error message below:
2012-04-09 12:22:10.353679500 starting delivery 5816: msg 46874631 to remote user@cardinalco.com
2012-04-09 12:22:10.353682500 status: local 0/10 remote 1/20
2012-04-09 12:22:10.402986500 delivery 5816: deferral: Sorry,_I_wasn't_able_to_establish_an_SMTP_connection._(#4.4.1)/
Notice the deferral message....
Obviously whoever is reviewing my case will want information regarding my MX record and such so here is a report from MXTOOLBOX.COM.
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mx:mydomain.com mx
Pref Hostname IP Address TTL
10 mail.mydomain.com ip.ip.ip.ip 60 min SMTP Test Blacklist Check
dns lookup ns lookup whois lookup spf lookup
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substituted the domain and ip info above for privacy....
Now our domain is not blacklisted anywhere so that's not the issue, the mx record is not the issue?, so what's the issue??
I have combed the internet with this error message and I am bleeding out of my eyes trying to either fix this or to be able to tell intermedia that its there issue. Any help is appreciated.