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10 Tips To Keep in Mind For a Smooth ESP Migration

10 Tips To Keep in Mind For a Smooth ESP Migration
Table of Contents
  1. Template item

What is an ESP?

An Email Service Provider (ESP) is the online software through which a company builds, schedules and sends email marketing campaigns. ESPs often have SMS capabilities, too. Some widely known ESPs are Mailchimp, Klaviyo, Drip, and Iterable. 

Why change ESPs?

There are numerous reasons to be considering moving to a new platform. The most common one is that you (or the email marketing team managing the ESP) can’t easily accomplish your daily email marketing tasks. For example, segmentation isn’t straightforward, or actions take too long to complete.

Another reason would be that there is additional functionality that your current ESP doesn’t offer, like accelerated mobile pages for email (AMP) and SMS marketing.

Or it’s simply contract renewal time, and you’re looking for a better deal.  In any case, there are a host of considerations when considering how to choose an ESP that you can read more about here.   

Is changing ESPs difficult?

Migrating to a new ESP is a complex project, but it is, by all means, doable. An ESP migration is disruptive and it may impact your engagement and revenue for a couple of months, but often the benefits outweigh the drawbacks. If your company will be better off for it, move forward. You just need to watch out for some common pitfalls. 

As for when to make the change, there's never a good time to do an ESP migration. Plan your transition for a quiet time that is at least a quarter away from your peak season, just to be safe.

How to manage an ESP migration like a pro

Having managed multiple migrations from and to different ESPs in my career, I’ve put together a helpful list to guide you on how to prepare and what to look out for at each stage of the process.

Before the migration

1. Contact all stakeholders

When you start preparing for an ESP migration, it’s worth running a meeting with all of your key stakeholders — even the ones you don’t initially think are affected. In general, email marketing touches many areas of a business, including, for example, landing pages and data analytics. By having a conversation with your stakeholders early on, you’ll be able to document any dependencies that you will need to factor into your project plan.

2. Start cleaning and mapping your data

An ESP transition is a great opportunity to do an exercise of data cleaning and mapping. Doing this before the data is in the new system is much easier than doing it afterward. Here's how:

  • Export your database and have a close look at the fields against a subscriber entry and the quality of data in each of the fields. This way, you’ll be able to find any duplicate information easily.
  • Remove any irrelevant or old data before uploading your database to your new ESP. You may have fields that you’re not using, especially if you’ve already changed ESPs in the past. 
  • Catalogue and compare the data fields of the two ESPs to easily map your data to the fields of the new ESP. For example, your current ESP may reference ‘sign_up_date’, while the name your new ESP gives to the same field is ‘created_date’. 
  • Merge any fields that have partial information and do some data completion. For example, if a customer’s ‘Shipping city’ is 'New York' but the field ‘City’ is blank, it’s worth also completing ‘City’ as 'New York' for future targeted campaigns.
  • Create flags to consolidate data. For example, say you get two separate lists from your old ESP, one for Customers and one for Subscribers. It’s worth turning this information into a flag in the database file you compile, so you have a single source of truth.

These actions may take some time in Excel, but clean and concise data is the basis for email marketing success, after all!

3. Project-manage the migration process

It goes without saying that to deliver an ESP migration you will need to put on your project manager hat. Like any other project, it is prone to delays, blockers and miscommunication. 

Make sure you get ahead of the problems by creating a project plan. Collaborate closely with your internal stakeholders as well as your external stakeholders — aka the support team, account manager (if available), and technical team of your new ESPs. This will be the key in completing the transition on time and with minimal frustration!

Scheduling a weekly check-in with the ESP team is a good idea to ensure progress is made according to plan.

Bonus tip: Double-check all work delivered. Catching a mistake at this stage can safeguard your deliverability later on.

During the migration

4. Transfer unsubscribes and bounces

Apart from loading subscribed contacts into your new ESP, you’ll also need to transfer unsubscribed and bounced contacts. This will ensure that suppressed customers don’t start receiving marketing emails suddenly. You may upload unsubscribed and bounced contacts in two separate files, which you download from your old ESP.

You’ll be uploading these alongside your opted-in database. Still, it’s also worth uploading daily updates of unsubscribes and bounces during the first month of the transition. There will be contacts who unsubscribed through an old email or bounced via an automation you still have running in the old ESP while you complete the transition.

If you don’t have an additional period of time for access to your old ESP, you may be able to request that the support team of the old ESP provide these files to you daily after your account has closed.

5. Implement content best practices

It may be a good time to audit your emails and examine where optimizations are needed. You may find there are some that need improvements or some that are no longer needed, which will reduce your migration time. It is also a great opportunity to identify gaps in your marketing and address them in the new system. 

Some common areas for improvement in automated emails before an ESP migration are:

  • Templates are dated / not in line with brand look & feel.
  • Imagery needs a refresh.
  • Mobile-first design needs to be applied.
  • The balance of images vs. text needs improvement.
  • Alt-tags on images are missing.
  • Products need to be updated. 
  • The user journey needs to be updated.

Applying email best practices is always important, but it becomes even more important when you’ve just switched to a new ESP as you’re trying to maximize engagement and prevent your emails from getting caught in the spam folder (more on that below). It’s also a good idea to A/B test subject lines to boost engagement rates in each send.

Depending on which ESP you are moving from, you may be able to download the templates, optimize them, and then upload them to the new ESP, alongside your core imagery for email templates, i.e., your header and footer images.

6. Warm up the IP address  

A key component of migrating to a new ESP is warming up the IP address. In simple English, this means allowing time for Internet Service Providers (ISPs) like Gmail, Yahoo, etc. to get familiar with your new IP address and recognize that your emails are of great quality and they do not belong in the spam folder.

In order to make that happen, you need to go through a process known as IP warm-up, which is perhaps the trickiest part of an ESP migration and certainly the reason many email marketers will choose to stick to their existing ESP.

Most ISPs will initially put emails that come from a new IP address in the spam folder, as a safety measure. The way to go around this is to create a send plan that includes daily sends of a small volume of emails per ISP, and start with your most engaged subscribers first. After the first round and depending on performance, you can gradually increase the volume of daily sends.

Apart from creating pots of data per ISP, you should also segment your data by country or region of activity. For example, U.S. vs. U.K. subscribers. 

This way, you can offer relevant content to each of your segments, and therefore have a higher chance of your audience engaging with your campaigns. This, in turn, helps increase the chances of your emails landing in the inbox rather than the spam folder.

Yes, what you are thinking is true. “All these different segments need multiple versions of the same email created!” That is true, and it is a process that is resource-demanding. However, if you’re ready to take your marketing to the next level and move away from one-size-fits-all emails, check out my other article on how to build an effective email marketing team.

7. Create ‘proof’ lists & ‘seed’ lists

It’s good practice to have both of these lists in your ongoing email operations.

A ‘proof list’ is the list of internal users that will proof emails before they go out. Depending on your ESP, you may be able to set it up as a list, or you may want to have the list of email addresses in a document from where you can easily copy them.

A ‘seed list’ is the list of internal users you want to ensure receive all emails. This usually includes higher level staff members, like the CMO or the founder. You want to set this up a separate list, so you can always include it in campaign sends, alongside the core audience of the campaign.

Before setting the proof and seed lists in your new ESP, it’s worth reviewing them for any team members who have changed roles and need to be removed or any new stakeholders who need to be added.

8. Connect sign-up forms

Once the warm-up is nearly completed, it is time to connect the sign-up forms to the new ESP so that new subscribers flow straight into the new database.

Allow plenty of testing time at this stage, especially if you’re hosting the sign-up form on your own website, as your tech stack may not connect seamlessly with your ESP straight away.

When this is done, you’re ready to launch your welcome flow in the new ESP. Just make sure you have tested all customer journeys vigorously, of course!

After the migration

9. Train your team

You made it to the other side! The migration has been completed and your new and shiny ESP is ready to be used. But don’t dive straight in!

Make sure to arrange for a training day as part of your new contract. If that’s not available, block some time on the calendar of the team members who will be using the ESP every day so that they can watch training videos and play around with the platform.

Discovering the full capabilities of this new tool and getting familiar with how to do things will prove useful down the line  — if, for example, you need to stop a campaign that’s already sending or figure out how to set up a dynamic banner in a campaign which is due to go out in 30 minutes. 

10. Keep an eye on results

Last but not least, look closely at reports during the first few weeks after launch. Do you notice abnormal open rates or unsubscribe rates? 

Don’t forget to check your brand’s social channels regularly and check in with your customer support team. If there are any customer complaints relating to email marketing, make sure to act on them quickly.

This way, you’ll be able to course-correct and prevent more customers from being affected.

Conclusion

To sum up, an ESP transition takes time and patience. It is a complex project, but by following these 10 tips, you are more likely to come out of it unscathed.

If you know you’d like to leave your current ESPs, but you haven’t decided which one to switch to yet, it’s worth having a look at this Mailchimp vs Klaviyo comparison.

Ellie StamouliEllie Stamouli
Ellie Stamouil is the founder of Aenae Marketing and an experienced email marketer specializing in lifecycle marketing and SMS. She can be found on Linkedin. Ellie has 10 years of experience in email marketing both in-house (Net-A-Porter, Walgreens Boots Alliance) and consulting start-ups and scale-ups. She has a master's in Marketing and has completed the Business Sustainability Management course at Cambridge University. She's helping businesses become more sustainable and communicate their sustainability efforts more effectively without compromising on profits.
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10 Tips To Keep in Mind For a Smooth ESP Migration

September 8, 2023
Ellie Stamouli

Table of Contents

What is an ESP?

An Email Service Provider (ESP) is the online software through which a company builds, schedules and sends email marketing campaigns. ESPs often have SMS capabilities, too. Some widely known ESPs are Mailchimp, Klaviyo, Drip, and Iterable. 

Why change ESPs?

There are numerous reasons to be considering moving to a new platform. The most common one is that you (or the email marketing team managing the ESP) can’t easily accomplish your daily email marketing tasks. For example, segmentation isn’t straightforward, or actions take too long to complete.

Another reason would be that there is additional functionality that your current ESP doesn’t offer, like accelerated mobile pages for email (AMP) and SMS marketing.

Or it’s simply contract renewal time, and you’re looking for a better deal.  In any case, there are a host of considerations when considering how to choose an ESP that you can read more about here.   

Is changing ESPs difficult?

Migrating to a new ESP is a complex project, but it is, by all means, doable. An ESP migration is disruptive and it may impact your engagement and revenue for a couple of months, but often the benefits outweigh the drawbacks. If your company will be better off for it, move forward. You just need to watch out for some common pitfalls. 

As for when to make the change, there's never a good time to do an ESP migration. Plan your transition for a quiet time that is at least a quarter away from your peak season, just to be safe.

How to manage an ESP migration like a pro

Having managed multiple migrations from and to different ESPs in my career, I’ve put together a helpful list to guide you on how to prepare and what to look out for at each stage of the process.

Before the migration

1. Contact all stakeholders

When you start preparing for an ESP migration, it’s worth running a meeting with all of your key stakeholders — even the ones you don’t initially think are affected. In general, email marketing touches many areas of a business, including, for example, landing pages and data analytics. By having a conversation with your stakeholders early on, you’ll be able to document any dependencies that you will need to factor into your project plan.

2. Start cleaning and mapping your data

An ESP transition is a great opportunity to do an exercise of data cleaning and mapping. Doing this before the data is in the new system is much easier than doing it afterward. Here's how:

  • Export your database and have a close look at the fields against a subscriber entry and the quality of data in each of the fields. This way, you’ll be able to find any duplicate information easily.
  • Remove any irrelevant or old data before uploading your database to your new ESP. You may have fields that you’re not using, especially if you’ve already changed ESPs in the past. 
  • Catalogue and compare the data fields of the two ESPs to easily map your data to the fields of the new ESP. For example, your current ESP may reference ‘sign_up_date’, while the name your new ESP gives to the same field is ‘created_date’. 
  • Merge any fields that have partial information and do some data completion. For example, if a customer’s ‘Shipping city’ is 'New York' but the field ‘City’ is blank, it’s worth also completing ‘City’ as 'New York' for future targeted campaigns.
  • Create flags to consolidate data. For example, say you get two separate lists from your old ESP, one for Customers and one for Subscribers. It’s worth turning this information into a flag in the database file you compile, so you have a single source of truth.

These actions may take some time in Excel, but clean and concise data is the basis for email marketing success, after all!

3. Project-manage the migration process

It goes without saying that to deliver an ESP migration you will need to put on your project manager hat. Like any other project, it is prone to delays, blockers and miscommunication. 

Make sure you get ahead of the problems by creating a project plan. Collaborate closely with your internal stakeholders as well as your external stakeholders — aka the support team, account manager (if available), and technical team of your new ESPs. This will be the key in completing the transition on time and with minimal frustration!

Scheduling a weekly check-in with the ESP team is a good idea to ensure progress is made according to plan.

Bonus tip: Double-check all work delivered. Catching a mistake at this stage can safeguard your deliverability later on.

During the migration

4. Transfer unsubscribes and bounces

Apart from loading subscribed contacts into your new ESP, you’ll also need to transfer unsubscribed and bounced contacts. This will ensure that suppressed customers don’t start receiving marketing emails suddenly. You may upload unsubscribed and bounced contacts in two separate files, which you download from your old ESP.

You’ll be uploading these alongside your opted-in database. Still, it’s also worth uploading daily updates of unsubscribes and bounces during the first month of the transition. There will be contacts who unsubscribed through an old email or bounced via an automation you still have running in the old ESP while you complete the transition.

If you don’t have an additional period of time for access to your old ESP, you may be able to request that the support team of the old ESP provide these files to you daily after your account has closed.

5. Implement content best practices

It may be a good time to audit your emails and examine where optimizations are needed. You may find there are some that need improvements or some that are no longer needed, which will reduce your migration time. It is also a great opportunity to identify gaps in your marketing and address them in the new system. 

Some common areas for improvement in automated emails before an ESP migration are:

  • Templates are dated / not in line with brand look & feel.
  • Imagery needs a refresh.
  • Mobile-first design needs to be applied.
  • The balance of images vs. text needs improvement.
  • Alt-tags on images are missing.
  • Products need to be updated. 
  • The user journey needs to be updated.

Applying email best practices is always important, but it becomes even more important when you’ve just switched to a new ESP as you’re trying to maximize engagement and prevent your emails from getting caught in the spam folder (more on that below). It’s also a good idea to A/B test subject lines to boost engagement rates in each send.

Depending on which ESP you are moving from, you may be able to download the templates, optimize them, and then upload them to the new ESP, alongside your core imagery for email templates, i.e., your header and footer images.

6. Warm up the IP address  

A key component of migrating to a new ESP is warming up the IP address. In simple English, this means allowing time for Internet Service Providers (ISPs) like Gmail, Yahoo, etc. to get familiar with your new IP address and recognize that your emails are of great quality and they do not belong in the spam folder.

In order to make that happen, you need to go through a process known as IP warm-up, which is perhaps the trickiest part of an ESP migration and certainly the reason many email marketers will choose to stick to their existing ESP.

Most ISPs will initially put emails that come from a new IP address in the spam folder, as a safety measure. The way to go around this is to create a send plan that includes daily sends of a small volume of emails per ISP, and start with your most engaged subscribers first. After the first round and depending on performance, you can gradually increase the volume of daily sends.

Apart from creating pots of data per ISP, you should also segment your data by country or region of activity. For example, U.S. vs. U.K. subscribers. 

This way, you can offer relevant content to each of your segments, and therefore have a higher chance of your audience engaging with your campaigns. This, in turn, helps increase the chances of your emails landing in the inbox rather than the spam folder.

Yes, what you are thinking is true. “All these different segments need multiple versions of the same email created!” That is true, and it is a process that is resource-demanding. However, if you’re ready to take your marketing to the next level and move away from one-size-fits-all emails, check out my other article on how to build an effective email marketing team.

7. Create ‘proof’ lists & ‘seed’ lists

It’s good practice to have both of these lists in your ongoing email operations.

A ‘proof list’ is the list of internal users that will proof emails before they go out. Depending on your ESP, you may be able to set it up as a list, or you may want to have the list of email addresses in a document from where you can easily copy them.

A ‘seed list’ is the list of internal users you want to ensure receive all emails. This usually includes higher level staff members, like the CMO or the founder. You want to set this up a separate list, so you can always include it in campaign sends, alongside the core audience of the campaign.

Before setting the proof and seed lists in your new ESP, it’s worth reviewing them for any team members who have changed roles and need to be removed or any new stakeholders who need to be added.

8. Connect sign-up forms

Once the warm-up is nearly completed, it is time to connect the sign-up forms to the new ESP so that new subscribers flow straight into the new database.

Allow plenty of testing time at this stage, especially if you’re hosting the sign-up form on your own website, as your tech stack may not connect seamlessly with your ESP straight away.

When this is done, you’re ready to launch your welcome flow in the new ESP. Just make sure you have tested all customer journeys vigorously, of course!

After the migration

9. Train your team

You made it to the other side! The migration has been completed and your new and shiny ESP is ready to be used. But don’t dive straight in!

Make sure to arrange for a training day as part of your new contract. If that’s not available, block some time on the calendar of the team members who will be using the ESP every day so that they can watch training videos and play around with the platform.

Discovering the full capabilities of this new tool and getting familiar with how to do things will prove useful down the line  — if, for example, you need to stop a campaign that’s already sending or figure out how to set up a dynamic banner in a campaign which is due to go out in 30 minutes. 

10. Keep an eye on results

Last but not least, look closely at reports during the first few weeks after launch. Do you notice abnormal open rates or unsubscribe rates? 

Don’t forget to check your brand’s social channels regularly and check in with your customer support team. If there are any customer complaints relating to email marketing, make sure to act on them quickly.

This way, you’ll be able to course-correct and prevent more customers from being affected.

Conclusion

To sum up, an ESP transition takes time and patience. It is a complex project, but by following these 10 tips, you are more likely to come out of it unscathed.

If you know you’d like to leave your current ESPs, but you haven’t decided which one to switch to yet, it’s worth having a look at this Mailchimp vs Klaviyo comparison.

Ellie Stamouli
about the author

Ellie Stamouil is the founder of Aenae Marketing and an experienced email marketer specializing in lifecycle marketing and SMS. She can be found on Linkedin. Ellie has 10 years of experience in email marketing both in-house (Net-A-Porter, Walgreens Boots Alliance) and consulting start-ups and scale-ups. She has a master's in Marketing and has completed the Business Sustainability Management course at Cambridge University. She's helping businesses become more sustainable and communicate their sustainability efforts more effectively without compromising on profits.

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