How do I switch Email Service Provider?


Within the guide you’ll learn everything you need to consider when looking for a new Email Service Provider (ESP), including:

  • Why you should be using an ESP in the first place
  • How you should map out your own business requirements
  • How to research and understand what the ESP provides
  • What you need to prepare before and during migration to your new ESP.

To make the research and planning even easier we’ve also create a Changing Email Service Provider Best Practice Checklist that you can download and keep track of your progress.

Why use an ESP?

First of all, email marketing has been proven to generate the highest ROI compared to every other marketing channel. In fact you’re looking at a 35:1 ROI. So for every £1 you invest, you get £35 back!

Then of course there are the issues you may encounter if you intend to send emails on a mass scale, but aren’t using an ESP.  This may include your email address becoming associated with SPAM, which will dramatically affect your email deliverability and sender reputation.

The right ESP will give you access to a myriad of tools to help you create engaging email creative, personalised campaigns that resonate with your subscribers, and automate campaigns along the customer lifecycle, so you can quickly scale your email strategy. The right fit ESP will also provide you with deep insights regarding the success of your email campaigns and the engagement of your subscribers, plus much more.

These points form just the tip of the iceberg for why you should use an ESP.  Throughout this guide we’ll delve deep into some of the awesome things the right ESP can provide for your business and what you should be looking for.

Creating your Proposal

So you’ve Googled ‘Email Marketing Solutions’ and you get 755,000,000 results. The top is filled with Adverts and there is a never-ending list of links through to comparison sites, blogs and news articles –  you could be there forever trying to decide which one to pick. But don’t just jump straight in as choosing an ESP can be a big decision and needs to be considered wisely.

Take a step back and put your plan together of what YOUR perfect ESP looks like. There are a wide range of areas you should consider in your proposal before you start reaching out to an ESP. Here are the key areas for consideration.

What volume and frequency of emails will you be sending?

How many emails per month are you planning to send? Different ESPs have different pricing structures and some charge per contact while others charge based on the volume of emails you send.  There are also tiered pricing models based on a number of different factors. So understanding exactly what your requirements are and putting them in your proposal is vital to you ensuring there is a good budgetary fit.

Knowing how many subscribers you have and how many emails you plan to send each month goes hand in hand with setting your budget. Your budget is an important part of your proposal when choosing an ESP as pricing can vary widely. A good ESP will be able to calculate your ROI from your email spend against your email strategy, especially if they have a customer success team that works alongside you to gain the most ROI from your strategy.

And even if you don’t have a strategy, a good ESP should be able to advise you on how to get started and how to progress and grow your email marketing over time.

What emails will you be sending?

Your proposal should also contain which types of email campaigns you plan to send, as well as the frequency. Will you be sending only a monthly newsletter?  Or do you want to create welcome, onboarding or lifecycle automation sequences? Do you want to build out particular lifecycle journeys? Do you need emails triggered by actions such as cart or browse abandonment?  All of these should be documented in your proposal.

What features do you require?

As mentioned above, you should also include which types of features you need from your ESP. A number of providers have very limited functionality so you can only create ‘batch and blast’ email campaigns compared to others who have enhanced segmentation, automation, personalisation and detailed reporting functions.

A critical part of your email campaign success is making sure your emails look good and are well optimised to display on a multitude of different devices, especially mobile as around 53% of emails are now opened on a mobile browser. Does the ESP have a visual drag and drop editor for you to easily create visually pleasing designs quickly and easily?

Then you need to consider sending your email and how your ESP can help. E.g. can you A/B test your email subject lines to ensure the highest open rates for your campaigns? You might also want to look for an ESP that uses intelligent time sending. This allows each subscriber to  receive your email at a time relevant to them, based on the time they are most likely to open the email, therefore increasing your open and engagement rates.

Of course informative reporting is a must from any ESP – what’s the point in sending your campaign if you don’t know how it’s performed? So ensure this is top of the priority list when checking out an ESP.

Another question to consider is ‘does the ESP have an API that can seamlessly integrate with your techstack?’ This could be your CRM or any other solutions through third party software such as Zapier. Integrations help increase efficiencies by letting all of your tech talk to each other, eliminating the need for manual work.  If the ESP does not have this, think about your future investment in technology and whether not having this integration feature could impact your future work efficiency.

Being with an ESP is usually a long standing relationship so choosing one that has a wide range of features works best as you can scale your requirements as your business or strategy grows. You don’t want to find yourself stuck with basic functionality that your business outgrows and then have to repeat this entire process again in the near future.

Who will be using the new email platform?

In your planning, take time to consider who will be using the new platform and what their levels of technical knowledge will be. Some ESPs have limited functionality within their email creation tools, so knowledge of HTML and CSS may be needed by the users. ESPs with drag and drop or WYSIWYG (what you see is what you get) editors are possibly the best choice, as very little technical knowledge is needed to create engaging email designs.

Also, ESPs have different pricing models based on the number of users or licences you require, so make sure you cover all of these bases within your proposal.

What services do they offer?

Some ESPs only provide the platform and no other additional services. While this may be cheap, it’s not very useful to someone looking for training or just help with using your new email tech to the best of its ability.

Choose an ESP that provides a whole host of services and solutions to complement your email strategy – from fully managed services to creative design services, technical training and strategic advice.

Are you looking for a customer success or account manager to give guidance on your email strategy? To help you review the ongoing successes and give strategic advice on where these can be improved? Make sure you know this before you put pen to paper and ask for examples or a free consultation if they do, to ensure quality of service.

Does the ESP match your GDPR requirements?

Using a respectable ESP will ensure that you comply with GDPR regulations when collecting email data.

You also need to consider where your ESP is geographically based and where their servers are hosted and check if these are inline with your GDPR terms and conditions.

Ask to see the ESPs GDPR terms and conditions and ensure they have their own Data Protection Officer (DPO) who is properly experienced in the areas of GDPR.

Does the ESP have a good reputation?

You need to do your research on the ESP and find out if they have a good reputation, are reliable and what is their deliverability rate like. There are a number of great resources online such as G2 and Capterra where you can find a wide range of unbiased customer reviews and comparisons.

Take some time to read the ESPs customer case studies and don’t be afraid to ask the ESP if you can speak directly to one of their customers.

Ask the ESP if they have use cases for the specific industry your business is in, take a watch of their webinars and checkout their resources such as white papers and best practice guides to see where they can add additional value to the services they offer you.

When researching ask for the ESP’s SLA (service level agreement) and response times to see if there might be a chance of regular downtime that could impact your business.

How is their customer service?

The following questions will help you determine the level of customer service your ESP can offer and whether you need it:

Does the ESP have a wide range of support resources and collateral to help you quickly solve any issues you may encounter?

Is there an onboarding stage that will help you kick start your campaign or are you just given a platform to figure out for yourself?

How do you contact their customer support? 

Do they use a ticketing system such as Zendesk where you can submit and issue or question and be kept uptodate with the status?  Will you have phone support? Don’t be afraid to ask these questions directly.

Ask them how you will be notified when there is maintenance or potential downtime – will this be by email,  or will you be contacted directly by your Customer Success or Account Manager? Finding this information out is vital as it can directly impact your business.

Have a demo and get to know the team

It’s vital that you have a demonstration or trial of the software before you sign. Ask for an online demonstration or physically meet the team that you’ll be working with – this will give you a great chance to not only see the solution and the features they offer but also see if their values are inline with your business.

Working with an ESP should be a close relationship, so take some time to speak and get to know your Customer Success Manager or Account Manager and research the heritage of the brand.

Implementation and contracts

A key area to understand is the ESP’s implementation process and contractual details.

Regarding implementation, consider asking if the ESP offers an email data healthcheck. Also check if they warm up the IP address your emails will be coming from to increase deliverability and check if you’ll be given a dedicated IP address.

You want solid timelines and to understand the onboarding process, or migration strategy if you’re moving from another ESP.  If you’re migrating, does the ESP ensure your unsubscribes are suppressed? Will they help segment your email lists and give you strategic hands-on advice to make the transition as seamless and painless as possible?

Be sure to fully read the contract and terms and conditions/service of the ESPs you’re considering. Look out for any hidden charges, break clauses or deadlines for rolling contracts before you sign anything. And if you have questions about the contract, keep going back until you’re satisfied and comfortable to sign.

10 things to do when switching to your new Email Service Provider

You’ve now chosen your perfect new ESP, you’ve done all your background research and checks, they have the features you desire, the team are awesome and the company is heading in the right direction.  Now it’s time to consider what you need to do in order to migrate to your new ESP.

To make it easy for you we’ve listed 10 things to do when switching to your new Email Service Provider.

  1. Transfer your email unsubscribe list

Before you make the switch, you need to gather several important lists of data from your existing ESP. First things first, make sure you have a list of unsubscribes. This helps you avoid making the mistake of sending to people who have already opted out.

  1. Get a list of bounces

Next up, get a list of all of your hard and soft bounces. Continuing to send to them via your new ESP may have a negative impact on deliverability.

  1. Transfer Spam addresses

It is important to transfer the list of email addresses you’ve identified as spam traps when switching ESP. Your email marketing may be spam-free but you can still be penalised if you start sending to spam traps from your new ESP.

  1. Clean your list

Switching ESP is the perfect time to clean your list. Who hasn’t opened an email this year? Now is the time to trim your list down to size. A smaller, more engaged list is good for deliverability.

  1. Use engagement history

Your highly engaged email subscribers are your secret weapon when switching ESP. Sending to this list first from your new IP address helps build your reputation as a sender. So, be sure to harvest your engagement history before switching.

  1. Bring across your sending domain

If your new ESP allows it, bring across your sending domain when switching. This is beneficial as you have built up your reputation on this domain. What’s more, you’ll already be added to your subscribers’ safe sender list which is a win for deliverability!

  1. IP Certification

If you use an IP certification tool to improve deliverability, be sure to let them know you’re switching ESP. A quick task, but one that’s easily forgotten.

  1. Gradually increase send volumes

Suddenly sending a large volume of emails from a new IP can lead to mail being rejected. This is because your Internet Service Provider (ISP) may view the activity as suspicious.

So, if you’re switching to a new dedicated IP, you’ll need to warm it up. IP warming is a process of gradually increasing send volumes over a number of days or weeks. This slowly builds up your sender reputation and improves deliverability.

  1. Check bounce and blocked rates after each send

As you gradually increase your send volumes, keep checking the bounce and blocked rates after each send. Avoid increasing your volume if these are over 5 percent to protect your IP’s reputation.

  1. Update sign-ups forms

Make sure your sign-up forms are updated or redirected to reflect the change in ESP. Neglecting to do this could mean people are unable to join your mailing list. Conduct an audit to ensure every form is updated.


We’ve covered a wide range of areas that you need to consider when looking to switch your Email Service Provider. As you now know, it’s super important that you do your research and compare a number of different providers before making your final decision.

Ensure they meet your requirements across a wide range of different factors including features, price, services, support, brand values, reputation and the other factors we have covered in this guide.

Once you’ve made your decision, make sure you follow our 10 things to do when switching to your new Email Service Provider to ensure you’re all ready to hit the ground running.

Good luck with your search. If you’re considering switching from your current Email Service Provider, get in touch with our experts and we’ll be happy to discuss your requirements and don’t forget to download our Changing Email Service Provider Best Practice Checklist.

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