Email is, on average, one of the better channels in a marketer’s toolbox. In 2023 it brought in an 8.7B revenue in the US alone — and half of all the marketers said their email ROI that year doubled compared to 2022. Migrating to a new ESP becomes a balancing act as a result.
However, you shouldn’t dismiss the idea of a switch if your current provider is not up to scratch. There are four common issues which are likely to push you over the edge — and force you to consider alternatives:
However, there is a case to be made against switching providers as well. Here are some of the instances you should opt against finding a new ESP:
Naturally, the first thing on the list is whatever prompted you to start considering a move away in the first place. We’ll go over some of the likely reasons:
Decide who will coordinate the migration
Depending on how many campaigns and subscribers you have, the process can take up to a month. That’s a sizable chunk of time — so avoid changing ESPs during your busiest business period.
Inform the stakeholders about the process: they might raise concerns or points you haven’t considered. Your sales and customer support departments should be kept in the loop too — so that they could answer questions from clients.
The migration will also require coordination between multiple departments: marketing and IT at least. Your email marketing specialist should be up to date with all the content involved — but they might lack the managerial nous to coordinate the process. Your head of IT or marketing might be better equipped for the job.
Analyze what needs to be carried over
That includes your subscribers’ lists, templates, images, automated email sequences and integrations. Contact your new ESP support team to see if some of these things can be carried over automatically, via API — and which integrations they offer that you need.
Be ready to use several ESPs for a while
Don’t jump ship from your old ESP straight after the migration process is over. A buffer period during which both ESPs are operational is a good idea for two reasons:
Notify your subscribers about the change
The swap will most likely affect the interface of your emails — and some more technical issues might pop up along the way as well. Let your customers know in advance why the migration is taking place — and assure them it’s under control.
Arguably the most important part of the process. The easiest thing to do here is find out if your new ESP offers a direct integration with the old one: this way importing subscribers will be relatively straightforward. However, check that all the contact info carried over correctly.
If there’s no direct integration with the new ESP, you can simply download all the subscribers’ data from your old as an Excel file — and then import it. We’d advise you to name all the subscriber segments the way they were called in your old service: consistency will make it easier to pinpoint missing data.
There are also several other important points to keep in mind when moving your database:
Much like with subscribers’ lists, a direct integration with your new ESP will make this step a breeze. However, if there is no direct integration — or if you have only a few dozen email templates — you can carry them over manually.
Simply copy and paste the HTML code for each template into your new ESP — and that’s it. Things might get trickier if your email templates have AMP content inside: that is, content that constantly updates, so that whenever the recipient opens your email, the AMP part of it will be brand new.
You should also check other interactive parts of your email templates, such as unsubscribe buttons. Finally, all images will need to be uploaded to your new ESP — and links to these images updated within the emails. Otherwise they won’t properly be displayed.
Examine which integrations (with your CRM and CMS, with your website forms, etc.) you currently use — and set them up in your new ESP service. Like with the previous points, it can be done by means of a direct integration — unless your new ESP does not integrate with some of the things you use. In which case you’ll need to bring your new ESP customer support team and your IT department into play.
We are talking about your transactional, welcome and triggered emails. They are easy to overlook when changing ESPs because they run on autopilot and don’t require a lot of monitoring. Here’s a short manual of how carrying over your automated emails might look like:
Be prepared to use both your new and old ESP services alongside each other for a while. As far as automated email sequences go, you’ll need to let all automations run their course in your old ESP.
This step becomes necessary only if you decide to request a dedicated IP address in advance. Only in this case will your new IP address become an unknown quantity to inboxes like Gmail and Apple Mail. As such, they are likely to treat large volumes of sent emails from a new IP address as spam. If you use a shared IP address from your new ESP warming it becomes redundant, as other companies working with this ESP are already using this IP pool constantly.
Warming up an IP address simply means starting small: sending a moderate amount of emails and gradually ramping up the volume as inboxes learn to trust you. We have gone over the specifics of how to properly warm up an IP address in our breakdown.
In a nutshell, it’s a good idea to target your most active and loyal subscribers first: they are most likely to open your emails, click links and perform other actions to convince email services that you can be trusted. There’s no definitive answer as to how many emails you should send for a proper warm-up — or how frequently you should send them. Below is an approximation of this process from us.
| Week | Number of recipients | % of email list |
| 1 | 2500 | 5 |
| 2 | 5000 | 10 |
| 3 | 10 000 | 20 |
| 4 | 15 000 | 30 |
| 5 | 20 000 | 40 |
| 6 | 27 500 | 55 |
| 7 | 35 000 | 70 |
| 8 | 42 500 | 85 |
| 9 | 50 000 | 100 |
Use both your new and old ESP for a while. This is practical for several reasons:
Once the subscriber activity in your old ESP winds down, you can stop using it — and fully embrace your new provider.
Changing ESPs is a big decision and should only be resorted to when serious issues with your ESP arise. These include exorbitant pricing, limited functionality, technical problems and poor customer support. Don’t go looking for a new ESP if your emails aren’t performing well or aren’t hitting the Primary inbox tab.
Look at the following factors closely when choosing a new ESP: pricing packages, functionality, deliverability rates, scalability, reliability, security, good support, and ease of use.
Finally, treat the migration as a project. Appoint the person (or people) responsible, plan the migration for a quiet business period, and then follow these steps:
