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Why would you want to change your email service provider?

There are many reasons why you’d want to change your email service provider (ESP) – cost, flexibility, reliability and functionality are a couple, but that’s not the purpose of this article.

As many brands find themselves looking for new solutions to the complexities of a cross-channel world I thought it would be a good time to point out some best practices for ensuring an ESP switch – regardless of the motive- is as painless and beneficial as possible.

Internet Service Providers (ISPs) have, over the past few years, taken control of their users’ customer experience and have started limiting the amount of mail their users receive helping to ensure only the most relevant messages are delivered. Because of this the dangers of not following best practice are more real than ever before – If you’re not careful you’ll be blacklisted and all your emails will go straight into the spam folder.

As any email marketer will tell you, this is referred to as your sending reputation and it’s incredibly important. If you have a bad sending reputation it’s likely that lots of your emails will go straight to junk mail folders and not be seen by the people you want them to be seen by.

The trick with email is that when you change systems, you have to build up your reputation once again so that the Internet Service Providers (ISPs) can easily identify your mail as something valuable. What follows are a few tips on how you can quickly build up your reputation during an ESP switch.

Authenticate your mail

Correct authentication is an important starting point for establishing a positive reputation with the ISPs and well worth doing. The two most common authentication methods are Domain Keys Identified Mail (DKIM) and Sender Policy Frameworks (SPF). DKIM ‘signs’ your emails and SPF checks your email is coming from an authorised address.

There is also a third authentication tool called DMARC (Domain-based Message Authentication, Reporting and Conformance) which allows senders to protect their customers by telling ISPs how to handle the mail if the authentication fails and whether it’s possibly a phishing or spoofing message.

Move suppression data

When you move platforms don’t forget to transfer all unsubscribes and bounce data from your old platform to the new one. You’d be amazed how many brands forget to do this.

Some senders decide to take the opportunity of changing platforms to try to reactivate addresses that have either bounced or unsubscribed while on their previous system. Other brands unintentionally don’t realise they need to migrate this data as well.

If you don’t move the suppression data to the new system it can result in either high bounce or  complaint rates – or both. This will likely result in generating a poor reputation from day one on your new platform – damaging the sender reputation of your new IP.

In addition, after 30days of using the new system you should export the suppression data from your previous vendor and update your new suppression list. This should remove any users who may have been missed during transition.

Check your data

Changing ESPs is a great time for you to make sure you fully understand all your data.  Do you know how active your data is and have you implemented any list hygiene programmes? If you haven’t, it’s the perfect time to reach out to your account team and deliverability specialists to review.

While the definition of ‘active’ could vary from sender to sender, in this context I mean when was the last time the user either opened or clicked on an email campaign.

It is important to build a positive reputation from the moment you start sending from any new platform. One tip here is to mail your most recently active users first – in this way you’ll be starting with a strong performing campaign and your sending reputation will benefit.

As you start to send more you start to include contacts which were active less recently. Many ISPs focus on the engagement levels of users for senders on new IPs so it is increasingly important for you to focus on this as well.


Remember, it’s important to only send to people who have opted in to receive your email communications. As marketers we should be thinking about the customer and their experiences at all times so we should not be emailing people who have not agreed to receiving communications.

Believe it or not your opted in subscribers hold the keys to your inbox placement. If you send to people who haven’t asked to be sent communications from your brand it is possible that not only are you potentially breaking the law but those users will also likely complain. If they do the ISP will then determine you aren’t a trustworthy sender—and may block future mailings.

Comply with the law

Every country you send to has its own laws and regulations that are designed to prevent the transmission of spam. These guidelines inform you on what communication is permitted in each given region. Knowing what countries you send too and complying with the rules they set is crucial to reaching customers in different customers without damaging your sender reputation.

To find out about different country laws click here.

Start slow

It’s tempting to send a campaign to all your subscribers as soon as you transition to a new platform.  However, sending in small targeted segments to your most engaged customers will give you the best start on building a positive reputation with the ISPs.

It allows you to show ISPs that people trust your emails causing your reputation to growly quickly. We always recommend that senders start by sending their most active users first and then slowly grow it from there.

Make sure your onboarding is as smooth as possible

Transitioning to a new ESP is an opportunity to leave the past behind and rebuild your sending reputation. However, in order to build a positive reputation it’s important that you start with the data and follow the best practices as highlighted above.

There’s no point in repeating the same mistakes and damaging your senders reputation from the start. Remember, as marketers we have to consider our customers and do all that we can to ensure our communications are relevant, interesting and useful – anything else is likely to annoy people. When contacts complain about your communications you run the risk of damaging your sending reputation so think of the customer first and make sure you are providing them with messages they actually want to receive.

Experian Marketing Services is the leading global provider of customer insights, data quality and cross-channel marketing. We help organisations intelligently interact with today’s empowered and hyper-connected consumers.

By helping marketers identify best customers, find more, and then coordinate seamless and intelligent interactions across the most appropriate channels, Experian Marketing Services can deepen customer loyalty, strengthen brand advocacy and maximise profits.