MX Lookup

What is an MX Lookup?

Although MX Lookup is not a real term, I like to call an 'nslookup -q=mx' an MX lookup. It is basically looking for the mx records (mail exchange records) for a domain.

Why use an MX Lookup?

If you want to know the names of the mail servers for a domain and the priority level, then you should do an nslookup -q=mx

Is an NSLookup with MX safe?

By all means! It is public knowledge, if you know how to look for it.

This page shows local mail exchanger information. Type the domain name only in the text input below. (i.e. - davidj.org) and then click 'MX Lookup'.

ENTER DOMAIN FOR MXLOOKUP

DOMAIN:

Please enter a domain above for nslookup -q=mx.

Observe Returns:
Look for preference =#, mail exchanger = server.name.info

Sort Preferences:
The lower number, when there are multiple servers, determines the order that mail will try to send on.

SMTP Check

Connect via telnet on port 25:
Telnet to port 25 to see if you can connect, if you can't, you have found your first problem.

Verify SMTP server accepts an email address.

Use smtp commands to send a test message:
If you connect, use mail and rcpt and data commands to send a test message.
mail from:: Who is it from?
rcpt to:: Who is it to?
data: Type some lines and then put a period by itself on your last line.
quit: To close the connection

 

 

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