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Windows DNS - MX lookup failure

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6 replies

by ltecson0627

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I'm setting up my own DNS server. Everything is working fine except for sending emails. I could browse my website and receive mails. But when I send an email, my email server returns an error stating that my return address is not formatted properly or it cannot perform a reverse lookup. I have created A, CNAME, MX and PTR records for my website. How do I fix this problem?

6 replies

by theohkm

try to debug first your dns using nslookup.
nslookup
set q=mx
serverdomain.com
set q=a
mail.serverdomain.com
set q=ptr
[server ip address in reverse order].in-addr.arpa

by theohkm

Manually debug the email problem by:

telnet mailserver smtp

..... followed by a series of SMTP commands.

by ltecson0627

Thanks for your suggestions. I've discovered that one of my domains (Domain A) is set to the same IP address used by the domain in question (Domain B). I forgot that the DNS of Domain A is hosted by another hosting company. So when a reverse lookup is performed, the DNS of the hosting company is looked up first before my DNS server. To solve this, I used a different IP address for Domain B.

by cg it

First need some more information like are you hosting your own email server? If so what O/S? What email service are you using? POP3? SMTP? X400? Since you can browse your public website [I'm assuming when you say you can its a public and not an intranet website] and you can receive emails [again assuming this is from a public source and NOT intranet emails] that your DNS server is providing ip to name resolution correctly [you wouldn't be able to browse your web site nor receive emails to you

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