Who Uses Custom MX Records?
Custom MX records are used to specify the routing of email messages, and are of particular use to those who have their website hosted by one provider, but their email by another.
This would be needed whether you are running your own mail server at a another hosting provider (or on your own machines), or if you are using a third-party mail system such a Google Apps (Gmail) or Zoho Mail with your own custom domain.
How do Custom MX Records Work?
Have you ever thought about what happens when you send an email? How does it get to its intended recipient?
When an email is sent, the sending mail server, or Mail Transfer Agent (MTA), queries the recipient Domain Name System (DNS) for the MX records of each domain, and uses that information to control the path your message takes and get the email to the right email address.
How MX Records Affect Server Usage
MX records specify both the mail servers to be used, as well as their relative priority.
Assigning multiple servers with different priorities is similar to setting up multiple phone numbers. If someone can’t reach you on your cell, they might try you at home, and then the office, and so on.
MX records work in much the same way.
The primary reasons for specifying multiple MX servers, and assigning different priorities to each, are load balancing and redundancy.
For example, here are Google’s MX records:
Additionally, you can assign a separate e-mail server to any particular subdomain.
Load Balancing with MX Records
If you specify multiple mail servers in your MX records, and assign them the same priority, mail agents sending mail to you will select one of them at random.
This random selection automatically distributes incoming mail across your several mail servers, decreasing the likelihood that any one of them will be overloaded and fail.
Backup Mail Reception
If you specify one or more domain MX record as being a lower priority (note: higher “preference numbers” denote lower actual priority), they will only be tried in the event that the higher priority server fails.
This allows you to specify one server as your primary mail server and another as a backup.
Don’t Plan for Failover
If your multiple mail servers are equally capable of delivering mail to you, and there is no real reason to prefer one over the other, it’s generally a bad idea to then specify one as primary and the other as secondary.
This is poor resource management, as you are setting yourself up for a failover situation in the case of high volume.
Instead, Do This
Assuming both servers can and will get mail to your inbox, it is a much better strategy to assign them the same priority and allow for automatic load balancing. Your user experience will be the same, and your fail-over potential will be much lower.
Using one of the servers as a backup system only makes sense if there is some reason that it is less capable of getting mail to you directly — for example, if you would need to manually release mail from it to your primary server in order to see messages in your inbox.
Who Should Use Custom MX Records?
If you are like most web hosting customers, chances are good that your website hosting provider is also your email provider.
High-Volume Messaging Users
However, many businesses, either because of their size or their business model, rely on high-volume messaging. Others may require greater redundancy (that is, multiple servers) to reduce latency and improve the chances a message will be delivered.
In both of these cases, a separate email server (sometimes at a second hosting company) is often a business requirement.
Should You Use Custom MX Records?
If this is the case with your site, or you simply want to improve mail performance, then you will need to have the ability to customize your Mail Exchange (MX) records.
How to Customize Your MX Records
Customizing your MX Records is usually very easy. They are typically available for editing in the domain manager portion of your control panel, usually near your nameservers.
Look For Domain Name Records
If you have your hosting account and your domain registration with two different companies, you’ll edit your MX records with the company that handles your domain name registration and DNS settings, not your web host.
The MX Records are a part of your domain’s DNS record, so if you can’t find how to edit your MX records, try looking for your domain name records. They are usually all in the same place.
Hosting for Custom MX Records
Most users will never have to reconfigure their domain name MX records, but if you do, it’s generally supported as a standard service with your host, and shouldn’t affect your plan pricing. Because the number of available servers and priority schemes vary, however, always check with your host for full details.
Features to Look for In a Host if You Need Custom MX Records
When looking for a hosting plan that allows custom MX records, I’d recommend looking for these complimentary features, ordered from most important to least important:
- Simple cPanel that allows MX record editing
- Dedicated IP address
- A high server uptime guarantee
- 24/7 support
- SSD disk space (for speed and reliability)
- Premium email service built-in (for convenience)
Pros and Cons of Custom MX Records
Not sure if you need custom MX records? Let’s break down the most common pros and cons.
Pros of custom MX records:
- You have more control over email management (can choose which client to use).
- If you do it well, you can handle high email volumes better than many hosts.
- You avoid email address limits set by hosts.
Cons of custom MX records:
- It’s an extra step in your website set up, and can be tricky if you’re not technical.
- Hosts can have better email servers than third party email providers.
- Most custom email servers have an additional cost to pay.
Top 3 Hosts for MX Records
Being able to customize a DNS MX entry on a domain name is a standard feature available on most hosts, so you have a wide array of choices.
But there are certain hosts that make it easier than others or have other features or that synergize with custom mail management.
Here are my top 3 recommendations.
Server uptime is still a crucial factor to look for in a host. If your server goes down, so does the ability to look up MX records.
Liquid Web is one of the few hosts to offer a 100% power uptime guarantee.
On top of having cutting edge server technology, all of their plans come at least partly managed, which means they take care of updates and security vulnerabilities to keep your server healthy.
Additionally, highly-trained support is available 24/7. Finally, you also get a dedicated IP address.
The only downside is the price, which is higher than most other hosting companies.
Host Papa is a North American-centric host that offers a standard cPanel with all of its accounts to manage your server and domains.
They offer both shared hosting and low-end VPS hosting.
The cPanel makes it easy to edit an MX or CNAME record.
The big advantage with Host Papa is the very low prices.
The performance isn’t top tier, but it’s still good enough for most small businesses, and has a 99.9% uptime guarantee.
Brinkster is a host that falls somewhere in the middle of those two previous hosts.
They offer everything from shared hosting to dedicated servers, all competitively prices.
They are one of the few hosts which offers both Linux and Windows hosting, which may be important for your website(s).
Additionally, Brinkster offers their own premium hosted email service.
If you’re looking for more powerful e-mail account management options, this could be the right choice for you.
You’ll benefit from the convenience of managing both services in one place.
Other features in Email
Custom MX Records Frequently Asked Questions
- In 10 words or less, what is an MX record?
A domain record directing email to a specific mail server.
- Is a mail exchanger the same thing as a mail server?
Yes. The terms mail exchanger, mail transfer server, mail server, and MX host all refer to the same thing: a server with software that allows the server to receive email. A mail exchange (MX) record is added to a domain to direct mail addressed to that domain to a specific mail server.
- Where do I find the addresses to use for custom MX records?
The email service provider you’re going to be using to receive your email will provide the addresses for your custom MX records. Typically, you can find them by accessing the email provider’s knowledgebase documentation.
- Where do I add custom MX records?
You will add the custom MX addresses as MX records to your domain. In order to do this, access the account where you purchased your domain name — this may be your hosting provider or a separate domain name registrar — locate the DNS editor and add the addresses making sure to use “MX” as the record type.
- What is TTL?
When you add MX records to your domain, you will see that you must specify a TTL or “Time to Live” value. This value is used to tell Domain Name System (DNS) servers how frequently to check for updates to the MX records. In many cases, 3600 seconds or 1 hour is used, but some DNS providers may require that you use a longer interval such as 4 hours or even a day. As long as you don’t change your MX records very frequently, you shouldn’t be too worried about this value. However, if you do anticipate changing MX records frequently, then a lower value will ensure that changes to MX records propagate throughout the DNS system more quickly.
- Why should I care what the TTL value is?
Let’s say that you use a TTL value of one week for your MX records. Things are going great, but six months later there’s some sort of kerfuffle and you must quickly change email providers, so you update your MX records and wait, and wait, and wait. Unfortunately, since you used such a long TTL value, it could be as long as a week before the new MX records propagate throughout the DNS system, and during that interval, email will continue to be sent to your old email provider. In other words, TTL values matter when you need to change your MX records.
- What is the priority value associated with an MX record?
If you specify multiple custom MX records, the priority determines which record will be used as the default mail server. Think of priority as a place in line. The record with the lowest value, typically 1, is at the front of the line and has the highest priority. This allows you to either specify a hierarchy of mail servers to follow in the event that the primary mail server fails, or it allows you to specify multiple MX records with the same priority so that the load of email is spread evenly between all servers.
- Do I have to use the priority values provided by my email provider?
Let’s say that your email provider gives you three addresses to use as MX records with priorities of 1, 5, and 10, respectively. You think to yourself “Well, I’ll just use 1 for all of them to load balance the mail servers.” Bad idea. When email service providers tell you to use specific priorities, there’s a good chance the backup servers are only designed to hold mail in a queue until the primary server comes back online. Use the priorities your email provider tells you to use.
- When can I use the same priority for all MX records?
Only when your email service provider says you can. Alternatively, if you’re setting up your own mail server(s), you’re free to configure them any way you like, and using the same priority is one way to help balance the load between the servers.