Query regarding MX records

Posted on 2008-10-07
Last Modified: 2013-12-17

I have a query regarding a server recieving mail.

Let's say I have serverA, I have an application that can receive email on

If I send mail from my Outlook which connects to Exchange on the same network, will the mail be received by the server?

Or do I need a specific MX record pointing to

It's confusing me a little!
Question by:kam_uk
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3

Expert Comment

ID: 22659813
Your exchange server needs to be able to resolve where to send mail for the domain The potential issues are if your exchange server is authoritative for the domain or, or if is not a domain on the exchange server then it needs to be able to resolve a DNS MX record for that domain.

If they are both internal, then put a primary DNS domain on your local DNS server and add an A record and MX record for servera, but this won't work for the outside world.

Author Comment

ID: 22664793
Hi there

Thanks for the reply.

I had a read of RFC 2821, and it has the following statement;

"If no MX records are found, but an A Record is found, the A Record is treated as
   if it was associated with an implicit MX Record, with a preference of 0,
   pointing to that host."

Does this mean that if there is no MX record for, its A record will be used instead as an 'implicit' MX record?

Expert Comment

ID: 22667315

I have never experienced that working. It may be in the RFC,  but you are dealing with manufacturers that may or may not have implemented all the criteria in their software - usually they haven't because not all recommendations are a good idea. In this case if someone hasn't got an MX record maybe they don't want mail to that domain and implementing the clause you mention just puts more traffic on the internet - just one interpretation that may be taken in this case.

Stick with an MX record, which definitely will work.
Does Powershell have you tied up in knots?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why


Author Comment

ID: 22668181

Ok, makes perfect sense.

Sorry - just one follow up questions - when you say, ""but you are dealing with manufacturers that may or may not have implemented all the criteria in their software ", do you mean the manufacturers of the software that is sending the mail, or manufacturers of the DNS system?

Let's say - for the sake of argument - that the RFC -had- to be followed and lack of an MX mean the A record should be used. Is it up to the programmers of the software that wants to send the mail that need to add this functionality, or up to the developers of whatever mail system that email passes through, or up to the developers of whichever DNS system is used?

Accepted Solution

tismetoo earned 500 total points
ID: 22669035
Hi Kam

This is up to the developers of the mail system that is responsible for delivering mail to the recipients domain. If you use a mail proxy it would be the responsibility of their provider, otherwise it is the writer of your mail system.

The DNS guys just respond to queries - not their responsibility to determine what records people decide to use or not.

Author Comment

ID: 22676116
Thanks...excellently answered, many thanks!

Featured Post

NEW Veeam Agent for Microsoft Windows

Backup and recover physical and cloud-based servers and workstations, as well as endpoint devices that belong to remote users. Avoid downtime and data loss quickly and easily for Windows-based physical or public cloud-based workloads!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article explains how to install and use the NTBackup utility that comes with Windows Server.
In-place Upgrading Dirsync to Azure AD Connect
This video discusses moving either the default database or any database to a new volume.
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
Suggested Courses

632 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question