Getting E-mail With Custom DNS
The purpose of this document is to provide a step-by-step guide for determining if you need any MX records, and how to set them up if you do.
These instructions make use of yourdomain.com extensively. This will always be replaced with your actual domain name when you are working with your account. Additionally, unless specifically told otherwise, do not enter any quotes ("") when filling out forms.
The following instructions apply to the Standard Interface only. If you are using the Expert Interface, you may with to view the examples for Expert users.
Do you need an MX record?
Before we go any further, if you have not yet read the KB article E-mail, Mail Exchangers, and DNS, then you should do so now, paying particular attention to the first two sections.
The first step in determining if you need any MX records is deciding how you will receive your e-mail. To receive e-mail, you need a mail server. Either you will be running the mail server yourself, or someone will run it for you. If someone is running a mail server for you, you will need to find out from them the hostname of that mail server.
With this in mind, we'll look at the three most common cases our customers fall into.
Case 1: Hosting Your Own E-mail
If you're running your own mail server, make a note of the hostname you've created that points to it - usually this will be yourdomain.com itself, or perhaps mail.yourdomain.com. However, if you've used our instructions for redirecting web requests to a non-standard port, you may have something like www2.yourdomain.com as the host pointing to your server.
Case 2: MailHop Forward, Relay or Backup MX
If you are using one of our MailHop services there are specific requirements for MX records. Please see the MailHop How-To for details on these MX records.
Note that MailHop Relay is most often combined with hosting your own mail server since its major reason to exist is ISPs blocking port 25.
Similarly, MailHop BackupMX is often combined with hosting your own server but can also be used with a third party e-mail hosting company.
Case 3: Somebody Else Hosting Your Mail
If a third party (not DynDNS.org or yourself) is hosting/providing your mail services you will need to contact them to determine what MX records you need to create in your Custom DNS zone.
One item of particular note here, some third party hosting companies persist in instructing customers to create MX records that point to aliases. If your e-mail hosting company has provided you with MX record data and our system refuses to accept this and reports:
(smtp.yourdomain.com.) Mail eXchanger (MX) records must point to hostnames that exist, and are host (A) records, not aliases (CNAME).
then the problem is most likely that your mail hosting company has provided you with an alias. You will need to do a query on the alias to determine the hostname this points to and enter this in place of the alias.
Example:
$ host smtp.example.com smtp.example.com is an alias for inbound-smtp.super-elite-isp.com inbound-smtp.super-elite-isp.com has address 10.11.12.13
In the above example you would need to enter inbound-smtp.super-elite-isp.com as the Mail Exchanger value instead of smtp.example.com
Creating the MX records
At this point you should have a list of one or MX records you need to create. If you have two or more MX records you need to create then you also need to know the relative preference for each. If you are unsure of what preferences you should be using, refer back to the KB article E-mail, Mail Exchangers, and DNS.
- Login to your account, go to the domain you want to set up mail for. You should see your domain name at the top of the screen, with three sections under it, headed by yellow bars.
- First, you will create the primary MX record for your domain. Click on the "Add A New MX" link, which will take you to the MX configuration screen.
- In the resulting form, leave the first field blank.
Note: this field will almost always be left blank and would be used only if you wanted to have mail delivered differently for hosts under your domain - if you had a server called
users.yourdomain.com, for example, and you wanted its mail directed somewhere else, you would enter "users" here.Leave the "Preference" field at it's default value of "5 -- Highest", and enter the hostname of your primary mail server into the "Mail Exchanger" field. Click on the "Add MX" button, and you should receive a confirmation that the MX record has been created.
- Click on the "Return to yourdomain.com" link to go back to the screen you were at before you added this MX record.
- If you don't have one or more "backup" mail servers then you are done at this point. Otherwise continue on.
- Now you will create the MX record for your backup mail server. Click on the "Add New MX" link under your newly created primary MX record to go back to the MX creation screen.
- Again, leave the first field blank. In the drop-down box
for "Preference", this time you want to select "10" - this will
cause the MX you're creating to be used only if the first one
you created isn't reachable for some reason.
Note: If you have multiple backup servers, you can either put them all at the same preference, or use the preference levels to set the order in which they're used. Just remember - a greater preference value means it's used later (has "lower preference").
Finally, enter the hostname of the backup server as the "Mail Exchanger", and click on "Add MX" to create this MX and get to the confirmation screen. - Click on "Return to yourdomain.com" to get back to your domain's overall listing. You can click on the linked hostnames in this screen to make any necessary changes or removals at a later time. If you have additional backup server to add, simply repeat from step 5 above. Otherwise you are done.
Examples for Expert Users
To change your MX Records using Custom DNS, follow these steps:
- Log in to DynDNS.
- Select My Services from the top right of the page.
- Select the zone you wish to modify.
- From the Custom DNS row, select Details.
- From the Add New Record section, enter a Host, TTL, and Data value.
- Change Type to MX
- Select Add Record
A typical MX record may look like this:
Host TTL Type Data domain.com. 43200 MX 10 mail.domain.com
For more information on the meaning of these values, please view the KB Article on MX Records