How To Find Mx Record For Office 365

One of the less well understood components of a working electronic mail organization is the MX record. I exercise observe a lot of It administrators looking afterwards Commutation servers who don't really understand what an MX record is and how they piece of work.

DNS Fundamentals

MX stands for "post exchanger". An MX record is a type of DNS record, so any understanding of MX records has to begin with an agreement of the fundamentals of the Domain Name System (DNS).

The most important role of DNS for the majority of u.s. is translating names into IP addresses and then that network communications tin can occur.

For example, when you type www.microsoft.com into your spider web browser, DNS is used to look up that name to determine the IP address of the server to connect to. The domain name in this example is microsoft.com.

And so if that is how a simple web browser connection is made, what near when somebody sends email to an @microsoft.com address?

Again DNS comes into play, simply this fourth dimension the await upwards is slightly different. The sending mail server will wait up the MX record in DNS by following a sequence along these lines:

Expect up the administrative name servers for microsoft.com
Query the microsoft.com name servers for the MX records
Look up the names of the MX records in DNS to get their IP addresses

If you were to run your ain manual DNS lookup of the MX records for microsoft.com it would await something like this:

C : \ > nslookup

Default Server : UnKnown

Address : 10.0.one.9

& gt ; set type = mx

& gt ; microsoft . com

Server : UnKnown

Accost : 10.0.one.9

Non - authoritative answer :

microsoft . com MX preference = x , mail exchanger = postal service . messaging . microsoft . com

post . messaging . microsoft . com net address = 94.245.120.86

So the IP address of the "postal service exchanger" for microsoft.com is 94.245.120.86.

MX Preferences

You may observe the "MX preference" in the output in a higher place and wonder what that is referring to. To better explicate it hither is another DNS lookup for the google.com domain.

& gt ; google . com

Server : UnKnown

Accost : 10.0.1.9

Non - authoritative answer :

google . com MX preference = 30 , mail exchanger = alt2 . aspmx . fifty . google . com

google . com MX preference = 50 , post exchanger = alt4 . aspmx . fifty . google . com

google . com MX preference = forty , mail service exchanger = alt3 . aspmx . l . google . com

google . com MX preference = 20 , mail service exchanger = alt1 . aspmx . l . google . com

google . com MX preference = 10 , mail service exchanger = aspmx . fifty . google . com

alt2 . aspmx . l . google . com internet address = 74.125.115.27

alt1 . aspmx . l . google . com internet address = 74.125.91.27

aspmx . fifty . google . com net address = 74.125.157.27

Notice that at that place are multiple MX records each with a different preference value. The preference is basically a mode of setting the priority of each MX record. The lowest preference is the MX with the highest priority, ie the one that a sending mail server should attempt starting time.

The purpose of multiple MX records is to either:

Provide some load balancing by using multiple MX records with the same preference gear up
Provide a backup MX that can be used if the primary one is unavailable

The backup MX may be another mail service server in your system at a secondary site that has less bandwidth available to it. Or it could be a server hosted past a tertiary political party that provides backup MX services. Either way the purpose is to give sending e-mail systems somewhere to ship messages rather than have to store them and retry later.

Where Should Your MX Records Point?

One time you understand what an MX record does you then need to consider where your MX record should actually be pointing. Here are a few existent world examples of where to signal your MX records.

If your arrangement receives email directly then your MX tape would point to a public IP accost for your firewall or net-facing e-mail server (eg Edge Transport server).

If your organisation uses a hosted cloud service for email filtering, and then your MX record would point to their IP address (or an array of IP addresses depending on which service you are using).

Those are but two examples. There are numerous different scenarios that exist such equally hybrid cloud/directly combinations, ge0-distributed networks, and so on. However in my experience with customers these are the ii most common scenarios.

By now you should take a basic understanding of what an MX record is and how they work. If you accept any questions delight experience free to ask them in the comments below.