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Email servers are complex, requiring multiple components to work together to create a complete setup. On top of this, the email domain needs to be correctly configured, with DNS records in place as necessary.
It’s a good idea to test the configuration of your server, to make sure emails you send out reach the recipient’s inbox, rather than their junk folder.
A great tool you can use for this is Mail Tester – a website which runs checks on the emails it receives, assigning a score to your setup.
Sending Your Email
The first thing you’ll need to do is obtain an email address from the site. You’ll be provided an auto-generated email address when you visit the site.
It’s as simple as writing out your email, and sending it to this address.
If you don’t have a GUI or email client set up for your server, take a look at our guide to sending emails using telnet. Just make sure the email is sent from the server you’re trying to test.
Once the email has been sent, use the ‘Then check your score’ button to have the site analyse your email.
The site will auto-refresh the inbox every 15 seconds, until an email is received.
Getting Your Result
Once your email is received, you’ll receive a result.
The result gives a score out of 10, along with a breakdown showing how the score was calculated. In addition, the site gives context to the result, explaining the likely fate of an email sent from your server.
We’ll break down each section, to explain what each part means.
SpamAssassin
SpamAssassin is a commonly used email filter, designed to filter out spam emails.
There are several security-related features SpamAssassin looks for, to improve your score. Using DKIM, and SPF will boost your standing in the eyes of SpamAssassin, as long as they are set up correctly.
Authentication
This section checks more security-related features, with some overlap with SpamAssassin.
Here, you can check your DKIM, DMARC and SPF are set up correctly. In addition, DNS and rDNS are checked, to ensure emails are coming from an authorised server.
Message Content
If you’re just sending a test message, you can ignore this section. The content you’re sending isn’t relevant to future emails.
If you’re planning to send newsletters, or other bulk emails, this section can be useful.
Blacklisting
Another method of preventing spam emails, some email service providers (particularly the large ones, such as Outlook) will use blacklists to totally block emails from certain domains.
Becoming blacklisted will cause your email domain to become essentially useless, at least, if you’re intending to send emails to external addresses.
Sending emails that are flagged as spam can lead to your email domain being blacklisted. It’s very difficult to remove your domain from a blacklist, which is why it’s important to ensure your email server is configured correctly before you start sending emails.
Luckily, Mail Tester wont submit you to a blacklist, making it a great testing tool.
If you’re using a residential connection, you might find your IP address is on a blacklist, submitted by your ISP. ISPs will often send bulk blocks of IPs under their control to blacklists, as residential connections are not usually used to host email servers.
Conclusion
Given the complexity of setting up an email server, having a tool like Mail Tester to check your configuration is vital.
Be sure to give it a check, to make sure your emails are reaching an inbox.