5 Best Practices While Moving to a New Email Provider

As companies grow and business needs change, so too do their technological requirements. Over 80% of small businesses rely on email services to acquire new customers and respond to client requests, illustrating the importance of selecting an effective email service provider.

There are many reasons why companies decide to switch email providers. From changes to internal processes to increased service demands. But once that decision has been made, it’s not always an easy task to migrate entire business operations to a new messaging platform.

For employers and entrepreneurs wondering how to change email providers without risking avoidable downtime, it can help to apply a structure to your email migration strategy. This process is best achieved by following 5 best practices while moving to a new email provider.

Table of Contents

Key pre-migration considerations

Before committing to a planned email migration, stakeholders should discuss a number of important considerations. Even when following a well-planned strategy, migrations can be logistically complex. Answers to the following questions will help to streamline the process.

Can your current provider help?

Many email providers will offer assistance to clients looking to migrate data between services. To avoid potential data loss, see if your current provider has a migration process.

Can your new provider help?

In a similar sense, your new email provider may be able to handle some of the migration process for you. Check your new email provider’s website to see if this service is available.

Can some data be archived?

Moving email providers can present a good opportunity to reassess data storage needs. It can be worth backing up and archiving some data to speed up your email migration process.

Do you have a deadline?

Depending on the size of the organization, it can take up to 2-3 weeks for a migration to be fully completed. If this affects your business, you’ll need time to plan around loss of service.

Have you informed your clients?

While emails sent during your migration will be received eventually, there may be a period in which client requests go unanswered. Make sure to forewarn affected parties long before the migration is planned to start. Set up an Out of Office message explaining the situation.

How to change email providers: 5 best practices

Now that you’ve taken into account the above pre-migration considerations, you should be able to start planning your email migration. These 5 steps will help businesses to choose a good provider, develop an effective strategy and commit to continual service improvements.

1. Thoroughly evaluate email provider options

Understandably, your first step should be to thoroughly evaluate all available options. A great email provider for one company may not be so well-suited to another. Meaning stakeholders must take the time to consider the unique needs and requirements of their specific business.

When researching and comparing email service providers, consider the following factors:

• Pricing: Price is not always reflective of quality, but free services will often have you pay in other ways. Create a budget weighing up service costs against key features

• Features: Necessities include a mailbox size of at least 100GB and the ability to use your business’ name as the domain in your email address. But also look for features like device sync, email tracking and high-quality antivirus tools to boost productivity and security

• Scalability: Business needs change fairly frequently, and no team wants to migrate email services every year, look for providers that offer scalability features like options to expand storage and integrate with wider project / customer management systems

• Customer support: 95% of companies use email as their primary communication tool, so you’ll want reassurance that problems will be addressed promptly at all times. Look for a provider that offers 24/7 customer support and frequent system updates

• User reviews: Reading unbiased user reviews will be the best way to find out how good an email provider actually is. Check reputable review sites and ask similarly positioned businesses which email providers they think offer the best service

2. Plan and test your data migration strategy

Once you’ve chosen a fitting email provider, and are happy with the level of service offered, you can begin to plan and test your data quality and data migration strategy. Plans must be comprehensive, covering every aspect of the migration in great detail. This includes the transfer of emails, contacts lists, calendars, scheduling systems and any other data relevant to your business.

For businesses wondering how to change email providers, it’s this step that usually causes the most trouble. Primarily as data can be easily lost if systems are not properly organized.

Source data audit

Start by performing a source data audit. Go through your existing email accounts and take note of all key settings, the number of active accounts and the mailbox size. This will help to keep track of all the important files and settings that must be transferred to the new system.

In regulated environments or enterprise migrations, this type of groundwork often feeds directly into a more formal GRC solutions, ensuring that data handling aligns with compliance, governance, and security expectations from the outset.

Email migration tools

Next, choose an email migration tool. These smart software application suites can be used to automate much of the process of moving data between different email service providers.

To ensure a smooth transition, look for an email migration tool that fits the following criteria:

• Supports both your source and destination email service providers

• Has an auto-sync feature to successfully merge data without duplicating files

• Has built-in encryption and authentication protocols to protect your data

• Can apply automatic updates to the system if needed after the initial migration

It’s wise to test this migration process using dummy files in a controlled environment before engaging in a full data transfer. This will help you to test the process without risking the loss of key files. Additionally, create backups of your data to protect against unforeseen issues.

3. Commit to effective communication and training

Now that your migration strategy has been prepared and tested, you should be ready to begin transferring data. However, as the temporary loss of email service will likely affect numerous stakeholders, you’ll need to make sure they’re aware of the coming transition.

Inform all stakeholders of the proposed email migration at least 2-3 weeks in advance. This will provide ample time for the affected parties to research the new system and raise any potential concerns. As part of this process, draw up a document outlining the proposed migration timeline and distribute training materials to help users adapt to the new system. Ensure that the document processing is handled efficiently to maintain a record of all decisions and communications related to the migration.    

To ease any questions and concerns regarding how to change email service providers, your issued training materials should include the following information:

• Timeline: Create and implement a project plan including a timeline of key events, including when the old system will go offline and when the new system will be fully operational

• Technical information: Write instructions detailing how users can access and set up their transferred accounts. Use simple terms that are easy to understand

• Communications: Give users information covering key changes in the new system (formatting / attachment handling etc) and offer them a way to communicate issues

• Evaluation: Set time aside to check all users are comfortable using the new system on the day of migration. Make sure project leaders are free to troubleshoot issues

• Post-migration tips: Take note of potential post-migration problems and draw up a troubleshooting document, this should help to streamline the transition

4. Make sure to prioritize security and privacy

No matter the size of the business, all email service migrations will involve the transfer of some sensitive data. Before engaging in an email provider migration, project leaders must ensure that data transfers are appropriately secure and compliant with privacy regulations.

All data transfers must be encrypted to prevent hackers from intercepting data in a readable form. So make sure that your new provider supports this process. Additionally, multi-factor authentication (MFA) should be used to secure all active email accounts. Alongside a main password, secondary credentials like a one-time PIN code can be used to improve security.

Almost 75% of reported data breaches involve some degree of human error. Including things like accidentally sharing credentials or leaving accounts logged in. Adding extra protections like encryption and MFA helps to mitigate cyber threats like identity theft and phishing by strengthening access controls.

In addition to the above, it’s wise to stick to the following email cybersecurity best practices:

• Strong passwords: 75% of common passwords can be cracked in under one second. Strong passwords will be over 16 characters long, and use upper and lowercase letters, and include both numbers and symbols. An open source password manager can assist in managing these passwords securely, reducing the chances of reusing weak ones.

• Access control: Access to users’ accounts must be secured using reliable access control software. Keep up to date with access control trends to find a fitting solution

• Social engineering: Train staff to spot and avoid phishing scams, spoofed emails and malicious links, as hackers can use these strategies to infiltrate IT systems

• Data backups: Frequently backup important data on an external hard drive or a server not associated with your primary email provider

• Software updates: Perform regular software updates to ensure new vulnerabilities are patched as promptly as possible

• Firewalls: Deploy firewalls to regulate incoming messages and filter out those that contain malicious links / files / malware

5. Develop a post-migration evaluation strategy

Learning how to change email providers must also include a well-planned post-migration evaluation strategy. This will involve an assessment of the full migration process, alongside efforts to collect feedback from users. This data can be used to inform future adjustments.

When evaluating your new business email system, make sure to check that:

• Cybersecurity tools are working as intended

• Notifications are sent to the correct addresses

• Updates and maintenance services are scheduled

• Integrated software (calendars / e-commerce tools etc) are working correctly

• Email filters are set up and operating as they should.

Additionally, create a feedback template to send to users requesting their opinions on key performance factors. This information can inform plans for future adjustments and training.

Useful prompts to consider include:

• Have you received any spam emails?

• Have you experienced log in issues?

• Are software integrations working correctly?

• Have your contact lists been updated?

• Are you missing any important data / files?

• Have you experienced any glitches / bugs?

• Are load times reasonable?

Consider any other important aspects of your business email system that could be optimized and add space for users to note down any other pressing concerns.

How to Move Your Email List to a New ESP Without Hurting Sender Reputation

Switching email service providers (ESPs) involves more than exporting your subscribers and importing them into a new platform. Your new sending infrastructure needs time to establish trust with mailbox providers like Gmail and Yahoo, even if you've been sending newsletters for years.

During a recent AMA, email deliverability expert LB Blair explained how she approaches large ESP migrations, including one involving millions of email addresses.

Her recommended process is to recreate your existing sending setup, test it, notify subscribers, and gradually move your most engaged contacts first. You can then use engagement data to decide how much of the remaining list is worth migrating.

Step 1: Understand which parts of your sender reputation will change

When you switch ESPs, you don't necessarily lose all the reputation you've built. Some of it is associated with your sending domain, while other parts are associated with the infrastructure and authentication identifiers used to send your emails.

Here's what to consider before migrating:

LB specifically warns about changes to the DKIM signing subdomain, because it can carry a reputation of its own.

"Just be aware at a technical level, the DKIM signing subdomain is gonna be different. And that carries a reputation. You are going to have to warm that up." - LB Blair

She also recommends sending bulk newsletters from a subdomain rather than your primary business domain.

For example, a company might use company.com for employee correspondence and news.company.com for newsletters. That helps separate high-volume marketing email from everyday business communication.

👉 If your current sending setup is working well, mirror it as closely as possible on the new ESP. A migration isn't necessarily the best time to change your sending domain, newsletter format, and sending schedule all at once.

Step 2: Set up and test the new ESP before moving subscribers

Before importing your entire audience, configure the new platform and verify that its sending setup works.

At minimum, check that:

• Your SPF, DKIM, and DMARC configuration is correct.

• Your sending domain is verified.

• Your From address and reply-to address work as expected.

• Your unsubscribe links and suppression settings function correctly.

• Your emails pass basic inbox placement tests.

LB recommends a particularly simple way to test your initial configuration: send an email with very little content.

Take the opening paragraph from your website's About Us page. Make it plain text, use a matching subject line such as About [Company Name], and include your normal email header and footer.

Then run an inbox placement test.

The idea is to test your sending setup without a complicated email template, large images, or numerous links introducing other potential problems.

For example, if a plain-text test performs well but your regular newsletter lands in spam, investigate the newsletter's content, links, images, and formatting rather than immediately assuming the new ESP's infrastructure is the problem.

If you're changing the sending subdomain as part of the move, treat it as a brand-new domain for warmup purposes. SendX's Auto Warmup now adapts the warmup plan automatically to a brand-new domain's actual daily sending room, rather than refusing to send until the domain catches up, so a fresh subdomain doesn't stall your migration timeline.

👉 Don't start migrating subscribers until you've successfully tested the new platform. Fixing authentication or configuration problems is much easier before you're sending thousands of emails through it.

Step 3: Tell your subscribers you're switching email platforms

This is a step LB particularly emphasizes.

Before migrating, send a short announcement through your existing ESP. Tell subscribers that you're making a change to your email sending system, when they can expect their next newsletter, and whether your sender address will change.

"Let your subscribers know in an email before you start the migration, especially if you're gonna change to a subdomain because they may have your contact saved." - LB Blair

For example, your announcement could say:

We're making a few changes behind the scenes to how we deliver this newsletter. You'll still receive the same emails every Thursday. If our next issue doesn't appear in your inbox, check your spam folder and add our sending address to your contacts.

This serves two purposes.

First, subscribers who have saved your previous sender address won't be surprised if it changes.

Second, regular readers will know to look for your newsletter if it doesn't arrive where they expect it.

LB notes that mailbox providers can be somewhat skeptical when a sender moves to unfamiliar infrastructure. Seeing the same subscribers engage with familiar content can help establish continuity.

👉 Send the announcement before the migration, while your existing ESP is still delivering reliably.

Step 4: Move your most engaged subscribers first

Once the new ESP is ready, resist the temptation to upload your entire list and immediately send a newsletter to everyone.

LB recommends starting with people who have engaged most recently.

"I always start any migration by just bleeding over the best contacts first." - LB Blair

These subscribers are more likely to recognize your emails, open them, and interact with the content. That gives your new sending infrastructure a better starting point.

You can divide your list into segments based on recent engagement:

These are illustrative segments, not universal deliverability rules. The right cutoffs depend on how often you send and how your audience behaves.

For instance, someone who reads a daily newsletter once every two weeks is different from someone who reads a monthly newsletter once every three months.

LB shared an example from her work during the acquisition of a company called Pier 1.

The company's historical database contained roughly 20 million records, including unsubscribes, complaints, and bounced addresses. But the previous organization had actually been sending to only about 4.5 million.

That distinction mattered. The historical database wasn't the same thing as the audience that should receive email.

LB explained that she recreated the previous sending configuration and filtered the list by its most recent engagers before starting the migration.

Her experience illustrates why list size alone is a poor basis for planning a migration. You need to know how many subscribers are currently eligible to receive emails and how many of those subscribers are actually engaged.

👉 Import your suppression records before sending and build your first sending batches from recently engaged, eligible subscribers. Don't treat every address in your historical database as an active subscriber.

Step 5: Warm up the new infrastructure by gradually increasing sending volume

After identifying your most engaged subscribers, begin sending to them in batches according to your new ESP's warm-up schedule.

The goal is to introduce your sending activity gradually rather than suddenly pushing your entire newsletter volume through new infrastructure.

LB recommends spreading messages across the day when the platform supports it.

"If you're able to spread them out by hour ... really throttle out that volume nice and slow and low, let the mailbox provider get used to you." - LB Blair

Suppose your newsletter has 200,000 active subscribers.

Rather than sending to all 200,000 on the first day, you would start with a smaller group of highly engaged readers. As the new infrastructure performs reliably, you would gradually increase volume and add the next engagement segment.

The exact number of messages in each batch should follow your ESP's recommended schedule and your actual sending history. There isn't one daily volume schedule that works for every migration.

Throttling matters as much as batch size. Sending 20,000 emails gradually over several hours creates a different sending pattern from delivering all 20,000 in a sudden burst.

LB noted that SendX and SendPost support throttling and that SendX offers a warm-up schedule to help manage this process.

Your warm-up plan should account for the volume you're moving, the infrastructure you're using, and how your emails perform as sending increases.

👉 Increase volume only while deliverability remains healthy. If bounces, complaints, or inbox placement problems appear, investigate before increasing the next batch.

Step 6: Keep your existing audience engaged while migrating

A large migration creates two simultaneous challenges: you need to establish trust with the new infrastructure while continuing to reach subscribers who haven't moved yet.

LB described both concerns when asked during the AMA whether a large newsletter should switch its entire list at once or operate on two ESPs temporarily.

Her advice was to keep serving the existing audience while gradually moving subscribers to the new platform.

If both ESPs are available, you can use them in parallel:

• The new ESP sends to the engaged segments that have already migrated.

• The old ESP continues sending to eligible subscribers who haven't migrated.

• Each subscriber receives the newsletter from only one platform.

For example, if you've migrated the 50,000 most engaged readers from a 200,000-person list, those 50,000 would receive the next issue from your new ESP. The remaining eligible audience would continue receiving it through the old ESP.

As more subscribers migrate, the audience on the old ESP gets smaller.

You also need to keep unsubscribe, complaint, and bounce suppressions synchronized so that someone who opts out doesn't accidentally receive emails from the other platform.

But running two platforms isn't always possible.

In LB's Pier 1 migration, the previous platform had already been shut off. She couldn't operate the old and new systems simultaneously, so she had to begin sending from the new platform without that overlap.

She still followed the same underlying approach: mirror the existing configuration, prioritize recent engagers, and gradually increase sending volume.

👉 If your old ESP remains available, use it to maintain your regular sending schedule during the transition. If it doesn't, focus on a controlled warm-up using your most engaged subscribers.

Step 7: Monitor deliverability without reacting to every small fluctuation

When you start sending from a new ESP, don't expect every performance metric to look identical immediately.

LB cautions that even a well-managed migration can cause a temporary dip in opens while mailbox providers become familiar with the new infrastructure.

She recommends balancing patience with responsiveness.

"Temporarily, you may get slightly lower open rates as the system gets used to you. You need to strike the balance between not making knee-jerk reactions to pull the plug and also being responsive to any potential problems." - LB Blair

Watch your delivery rate and engagement data as each batch migrates, particularly:

• Bounce rates: Are messages being rejected or failing to reach recipients?

• Spam complaints: Are subscribers marking your newsletter as unwanted?

• Inbox placement: Are test emails landing in inboxes or spam folders?

• Opens and clicks: Are your migrated subscribers continuing to engage?

• Mailbox-provider diagnostics: Are Gmail or other providers flagging authentication, compliance, or delivery issues?

For Gmail-related problems, LB recommends checking the newer version of Google Postmaster Tools for diagnostic signals.

If performance suddenly drops, her advice is to investigate before blaming the migration itself. The problem could involve email content, broken or insecure links, images, or sending configuration.

It's also important to compare similar subscriber groups. Your most engaged readers on the new ESP will naturally perform better than the less engaged audience remaining on the old one.

That difference doesn't necessarily mean the new ESP is delivering better or the old ESP is deteriorating.

👉 Look for sustained problems and investigate their causes. A modest, temporary decline in open rates is different from a sudden spike in delivery failures or spam complaints.

Step 8: Use migration data to decide when to stop moving subscribers

One of LB's more interesting recommendations is to use the migration itself to identify subscribers who may no longer be worth emailing.

As you move engaged subscribers to the new platform, the list remaining on your old ESP will naturally contain a larger proportion of inactive readers.

That can give you useful information about where engagement starts to drop off.

Imagine you've migrated everyone who engaged within the last 90 days, and that audience is seeing open rates above 50%. Meanwhile, the remaining audience on your old platform is getting a 20% open rate.

Those percentages are illustrative, but the pattern tells you something important. The people who haven't migrated yet are less engaged.

Instead of automatically migrating every remaining contact, examine engagement by recency.

For example:

Again, these are examples. A monthly newsletter may need a different definition of inactivity from a daily newsletter.

LB's point is that you can find a level of inactivity beyond which subscribers rarely begin engaging again.

Rather than carrying all those contacts into the new system, you can put eligible inactive subscribers through a re-engagement flow and retain the people who show renewed interest.

For contacts who remain inactive, stopping sends may be the better decision.

👉 Don't make migrating 100% of your historical contacts the goal. Aim to migrate the audience you can continue reaching and engaging responsibly.

Step 9: Complete the migration once the new ESP is performing consistently

Once your active subscribers have moved and sending performance is stable, you can finish retiring the old platform.

Before shutting it down, confirm that your important lists, automations, signup forms, suppression records, and reporting needs have been accounted for.

Check that new subscribers are entering the correct workflows and that nobody is receiving duplicate messages.

Then continue monitoring deliverability as your full sending volume settles onto the new platform.

The main lesson from LB's approach is that a successful ESP migration is gradual, but it doesn't need to drag on indefinitely. Configure and test the new platform, communicate with subscribers, move engaged contacts in controlled batches, and use the data to decide where the migration should end.

That gives your new infrastructure time to establish trust while protecting the audience you've already worked hard to build.

Related reading

• For the authentication records your new platform needs before you move a single contact, see SPF, DKIM, and DMARC setup.

• To know what "good" looks like once you're moving contacts, check email deliverability rate benchmarks by sending type.

• If your marketing and transactional mail share a domain, a migration misstep on one can drag down the other; see why separating transactional and marketing email protects the stream that's still working.

• If you're mid-migration and seeing a placement drop right now, inbox deliverability walks through triage steps.

Summary

Using the information covered in this guide, business owners should understand how to change email providers without facing avoidable downtime. Begin planning your migration at least 2-3 weeks before you intend to move, making sure all stakeholders have been notified.

Thoroughly evaluate all available options, considering key aspects like pricing, features and scalability. Plan and test your migration strategy, communicate plans and training clearly and make sure to prioritize security throughout all steps. Finally, create a post-migration strategy to check everything is working correctly and collect user feedback to inform service updates.