Email Best Practices – Why, When and How to Test

Every marketer will tell you that testing is one of the most important aspects of a successful email program. There are so many tests to run – A/B testing, subject line testing, content testing, time of day testing, etc. The problem is that there is never enough time to run every test, and more often than not, most marketers don’t make the time to measure the success of the email. That is a mistake that can negatively impact revenue.

Image via creativecrandall.blogspot.comHowever, deliverability testing should always be part of every email marketer’s toolkit. By not running these series of tests, emails could be landing in the recipient’s junk folder, never making it in the inbox. Many of these tests can be automated and email deliverability teams and services (including ANNUITAS) run these for clients on a daily, weekly, and monthly basis. So what types of tests are best practice?

  • ​Seed list testing-
    Includes sending the campaign emails to multiple email addresses, at different Internet Service Providers (ISPs) and networks, to identify where the emails are landing. Many ISPs and networks have different levels of filtering and by sending to these seed list email addresses, it may be easier to identify and break down which networks are sending the emails to the junk folder. After sending to these seed list emails, identify which ones landed in the inbox, the junk folder, or never got delivered.
  • ​​Content filtering and analysis testing –
    Includes sending the campaign emails to multiple email addresses that are being run through different filters such as Barracuda, Cloudmark, MessageLabs, etc. Again, sames as seed list testing mentioned above, take the time to evaluate the scoring for each of these filters and identify the cause. These filters change multiple times a day and that is why it is very important to constantly test and make sure emails are landing in the inbox.
  • ​IP and domain blacklist testing –
    Includes checking the Internet Protocol (IP) and domain across many different blacklist providers. Checking these blacklists will help determine if there is an issue with the email campaign program, list, content, etc. Many of these blacklists will affect the emails getting delivered to the recipient’s network, not to mention, making it in the inbox.
  • ​Authentication testing-
    Includes making sure that the emails are still passing Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) checks. Both SPF and DKIM are email authentication technologies that are essentially your “passport” to the network you are sending to. These technologies validate that you have permission to send using the supplied IP address and domain. Often, we find that someone may make a change to a Domain Name System (DNS) record that may affect these authentication technologies to fail.

Deliverability testing should be run before every campaign and especially when there are changes to ongoing automated email sends. Keeping an eye on the overall deliverability health for the email campaign will help IP and domain reputation stay high. Want to learn more about email deliverability testing? Contact us for a free deliverability health check and to discuss additional service offerings.

Author: Chris Arrendale CIPM, CIPT, CIPP/US, CIPP/G @arrendale is Chief Deliverability and Privacy Strategist, ANNUITAS

Image: Courtesy of

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