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We have email validation tool which tell, is valid or invalid by checking MX record ect.

It is working fine in my old server. Same build which i have deployed in another server Windows 2012, is not working, may be fire wall is blocking ?

I have opened port 25 in both InBound and OutBound

What i need to do ?

In that tool, which query MxRecords DnsQuery

TylerH
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Chandan
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  • Just an aside: having an MX record is not essential to having a valid email address. And an invalid email address may have a valid MX record. You're never going to get this perfect - you will still only be able to say "invalid" or "don't know". – Adrian Wragg Oct 30 '14 at 12:52

1 Answers1

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Your issue is that you've confused the port for SMTP (25) with the port for DNS (53). Open 53 and you should find that your queries work. Note that you will need to open it for both TCP and UDP; packets at or below 512 bytes use UDP, above that use TCP.

More information can be found on Wikipedia.

Adrian Wragg
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