Switching email vendors can mean a lot of moving parts and, if you’re like most marketers, a lot of questions. While you’re likely focused on the specifics of breaking in a new system, there might be one thing you had not considered – email deliverability. When thinking about email deliverability and moving to a new email service provider (ESP), there are a few things to remember to ensure a smooth transition.

First, while you will be sending from new IP addresses, you will carry your domain reputation with you. The most important thing you can do for email deliverability when switching email service providers is to start sending through the new provider using the best data. There is data at your old ESP that you will want to take with you. All the email addresses from subscribers that unsubscribed, marked your email as spam, hard bounced or became undeliverable (more than three soft bounces) will need to be suppressed in the new system.

Honoring unsubscribes have both an email deliverability component and a legal component. Unsubscribes should be recorded at the company level and be ESP agonistic. If I unsubscribe from a company’s email, I expect them to stop sending me email. I don’t expect to start receiving email again if they switch ESPs.

The other data components that need to be considered, spam complaints and bounces, have only email deliverability impacts. Sending to invalid recipients, recipients that have marked your email as spam, or receiving large volumes of bounces can impact your sender reputation. If the old ESP has already “cleaned that data out,” you certainly want to avoid sending to those recipients again.

To follow best practices, I always think unsubscribes should be preserved instead of removing the email address from the marketing population. If the latter is done and the recipient is reintroduced to the marketing population, the unsubscribe won’t be honored. As for the other data points, either removal from the database or suppression will work. To learn how to import unsubscribes and suppression lists in ClickDimensions, see this help article.

While we are on the subject of cleaning up data, removing unengaged subscribers periodically will help keep data fresh (not to mention improve campaign metrics). We usually recommend doing this at least every six months, but historical data is needed. If you have subscribers that haven’t opened or clicked in nine to 12 months, there are good reasons to suppress them. You will want to retain some of the engagement data from the previous ESP to help with this process. We will get into more detail about the why and how of unengaged subscribers in an upcoming post.

Lastly, and probably the most straightforward tip when switching ESPs, make sure that whichever sending domain is chosen that the necessary DNS records are in place prior to sending. Is your SPF record updated? Do you have DMARC in place on the sending domain? Is the email CNAME configured properly? If you are a ClickDimensions customer, we are happy to help with these items during onboarding.

To recap, when moving to a new ESP, you don’t want to cause any harm to the sending reputation you have worked hard to establish. During the transition you will need data from your old system to:

  • Bring over any email addresses that need to remain suppressed (unsubscribes, spam complaints, hard bounces and undeliverables)
  • Bring over unsubscribes so those recipients remain unsubscribed
  • Query the historical data to identify the email addresses that are unengaged, so they can be removed

That way you can start with your best foot – er, data – forward.

Happy Marketing!