Thursday, 3 May 2007

Exchange SMTP Problems

Checking you email server setup is a very importent because its better than having users telling you they are not able to send email, and that's just one reason.

You can check your domain name record by doing a domain name look up also called a NSLOOKUP here is an example lookup.

C:\Documents and Settings\Administrator>nslookup

Default Server:

> set query=any



primary name server =
responsible mail addr = serial = 2007032026
refresh = 1800 (30 mins)
retry = 900 (15 mins)
expire = 604800 (7 days)
default TTL = 3600 (1 hour) nameserver = nameserver =
MX preference = 10, mail exchanger =
MX preference = 20, mail exchanger =

text = "v=spf1 mx ~all" internet address = internet address = internet address = internet address =

Now you check your mail server has a revise domain name record setup, if it doesn’t the some mail server such as AOL and Yahoo and others will not accept email from you.

>set query=ptr
Server: []
Non-authoritative answer: name = nameserver = nameserver = internet address = internet address =

Make sure you FQDN (Fully Qualified Domain Name) on the server matches the MX record; you can do this by telneting to your mail server.

telnet 25

You should see a response like.

220 Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959

If you receive a response like the one below then you’ll need to make some changes as it is also a technical violation of RFC821 4.3 (and RFC2821 4.3.1)

220 Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959

If you follow all these rule you should be able to email anyone and everyone.

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