Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Public MX Records and Priority?

Posted on 2013-05-27
6
Medium Priority
?
382 Views
Last Modified: 2013-06-19
Can you explain a public MX record and oriority?  If an MX record is attached to a public IP and friendly name how does the priority work?  Is a priority 5 higher than a priority 10?
0
Comment
Question by:iNetSystem
[X]
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
6 Comments
 
LVL 23

Expert Comment

by:Stelian Stan
ID: 39199524
The lower the number is the higher the priority. Like you said 5 is higher then 10.
0
 
LVL 4

Accepted Solution

by:
iammorrison earned 2000 total points
ID: 39199528
A Mail Exchange (MX) record is a DNS object that is used to resolve email domains for SMTP. Even if DNS records exist for domain yourcompany.com ( if they have a website for example) if this domain wants to receive email, then it must also have a valid MX record pointing mail traffic to authorized mail server(s). Priority is given to the MX record with the LOWEST numbers first. To use your example, a record with a priority of 5 takes precedent over a record with priority 10.
0
 
LVL 4

Expert Comment

by:EddyvanOpdorp
ID: 39199556
Correct, how lower the number, how higher the priority.
If you have 2 record with the same priority it is random. This is called round robin.
0
Q2 2017 - Latest Malware & Internet Attacks

WatchGuard’s Threat Lab is a group of dedicated threat researchers committed to helping you stay ahead of the bad guys by providing in-depth analysis of the top security threats to your network.  Check out our latest Quarterly Internet Security Report!

 
LVL 44

Expert Comment

by:Amit
ID: 39199589
0
 
LVL 63

Expert Comment

by:Simon Butler (Sembee)
ID: 39199971
Of course everything about priority is theoritical.
In practise you will have email go to all hosts in the MX record, and if you have one with a higher cost then it will get more spam, as spammers target them.

I work on the basis that the priority means nothing, I don't use it with any of my clients. If they have multiple servers able to receive email then they all get the same cost - 10.
I don't believe that there is any round robin in MX records.

Simon.
0
 
LVL 47

Expert Comment

by:Craig Beck
ID: 39202633
In my experience the priority is not theoretical at all.

I have a MX record pointing to my primary SMTP server which is authoritative for my domain, but I also have a MX record pointing at a fallback SMTP server which isn't authoritative for my domain - it just acts as a relay so that if my SMTP server becomes unavailable it will store-and-forward.

Some of my clients have geographically distributed mail servers which manage the same domain.  The priority is the same on all MX records and mail delivery is totally random (as implied by round-robin DNS resolution).  If the SMTP server with the lowest priority is unavailable, the next SMTP server with the same priority isn't used though - the one with the next preferred priority is used.
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

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

One-stop solution for Exchange Administrators to address all MS Exchange Server issues, which is known by the name of Stellar Exchange Toolkit.
If something goes wrong with Exchange, your IT resources are in trouble.All Exchange server migration processes are not designed to be identical and though migrating email from on-premises Exchange mailbox to Cloud’s Office 365 is relatively simple…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

618 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