A practical guide for email marketers — Stripo.email

Switching your email service provider (ESP) or customer relationship management (CRM) system is more than just a technical task — it’s a strategic decision that can impact your email marketing performance. Regardless of the reason for switching to a new platform, the transition comes with both great potential and significant risks. 

You can clean up your data, improve workflows, and adopt better features — but you also risk breaking automation flows, losing valuable segments, or compromising data security. In this guide, we’ll explain how to transfer data safely and efficiently during an ESP or CRM migration without losing key assets or compromising sensitive customer information.

Why data transfer during ESP/CRM migration is a challenge 

Email marketing platforms store more than just contact data — they also retain dynamic fields, interaction history, custom segments, behavioral triggers, automation flows, templates, reports, and more. Your ESP can access all the data in your email campaigns, contact lists, and templates.

CRM systems, especially when paired with email marketing automation, also store sensitive customer data to help you manage relationships throughout your customer journey.

Two sets of challenges arise during migration:

1. Migrations can be messy: Data structures differ, automation logic may not transfer 1:1, and infrastructure changes can affect deliverability.
2. Careless migration can cause data loss: Some fields can be simply lost and not transferred, and there is also a risk that data will be exposed to third parties.

This can disrupt workflows or, worse, violate GDPR and compliance. Therefore, for an email marketer, understanding the technical and legal aspects of data migration allows you to protect your contact list and ensure business continuity.

Common reasons why companies switch ESPs or CRMs 

This article is about overcoming the risks and difficulties of migrating to a new platform. However, a reasonable question could be: Would it be better not to change anything and use the system in which you have already started working?

However, practice shows that changing the ESP or CRM platform in cases of inconsistency with business tasks can have a significant positive impact on your email marketing effectiveness and overall business performance. You should not remain “hostage” to a platform you have already outgrown or where the service has ceased to satisfy you.

Here are some common reasons why businesses might change their ESP or CRM platforms:

• outgrowing current functionality and looking for something better: Modern ESPs offer powerful features like advanced segmentation, automation workflows, A/B testing, AI, and in-depth analytics. If your current platform lacks these tools, you’re likely missing opportunities to personalize campaigns and increase ROI;
• scalability: As your subscriber base grows, so do your demands. You need a platform that can send high volumes of emails reliably without slowing down or dramatically increasing your costs;
• deliverability concerns: If your emails consistently land in spam or don’t reach inboxes, it could be due to poor sender reputation management or outdated infrastructure. Switching to an ESP with stronger deliverability tools can significantly impact engagement;
• poor integration: Your ESP should work seamlessly with your CRM, eCommerce platform, and other tools. If the integration is clunky or requires constant manual syncing, it might be time to find a provider with smoother, more reliable connections;
• limited support or user experience: Timely, helpful support is crucial, especially during campaign launches or technical hiccups. If your current ESP lacks responsive service or has an unwieldy interface, moving to a platform with better UX and support can save time and stress;
• pricing and value don’t match: Sometimes, the issue is simple: the cost no longer matches the value. If you’re paying more for less, considering more affordable platforms that deliver the same — or better — functionality is worth exploring.

If you see one or more reasons in this list that make you think about changing platforms, you already have criteria for choosing a new tool. You can use all the points listed above to select a new platform.

Pre-migration planning: What to do before moving a byte 

Once you’ve explored your new platform’s features during a free trial, it’s time to prepare for data migration.

Audit your data

Migrating between platforms is like moving into a new house, during which you can conduct an audit and take only the truly necessary and valuable things with you. Sometimes, platforms collect and save a lot of unnecessary or outdated data that should not be transferred to a new system. 

First, determine what data needs to be transferred: subscriber lists, consent information, behavioral data, engagement metrics, and automation chains are typical. If you see something that is already outdated, feel free to delete it. You should make a list of what must be transferred.

Clean your contact list

Remove invalid, inactive, or duplicate email addresses from your subscriber lists. Migrating to a new platform will improve your delivery and engagement rates. Also, be sure to check your subscription permissions and unsubscribe settings to make sure they are up to date.

Document your workflows and automation

Of course, we expect to be able to migrate all campaigns and email chains fully. If something goes wrong, map all campaigns based on triggers, API calls, and integrations, and mark your segments. All this will help you create new campaigns in case of loss.

Back up everything

Backups are your Plan B if any technical issues arise during migration. Download full data exports and automation logic, where possible. For example, export subscriber lists to a CSV file and archive your most important email templates, past campaign reports, and workflows.

What to pay close attention to during migration

Modern ESPs and СRMs make data transfer quite seamless and straightforward. However, you should still pay special attention to such data components to ensure the security of the transfer operation.

Contact lists and segmentation

Export all fields of your contact lists carefully. Pay attention to how fields with email addresses, names, tags, custom fields, consent dates, etc., transfer to avoid losing information or creating a mess. Segments also need to be transferred in this stage.

Keep the opt-in source and GDPR/CCPA flags intact.

Content and email templates

Email marketers who create email templates and all content at once in their ESP editor often experience difficulties later due to the need to rebuild email templates when moving, since different ESP editors may be incompatible. And yet, if you used them:

• save all email templates in HTML and AMP formats;
• check for compatibility issues with the new ESP’s editor;
• re-upload assets (images, hosted files).

Triggered and automated campaigns

Triggered and automated email campaigns save not only the emails themselves but also the data and the logic of the chains on which they are sent.

You will need to take the following steps:

• manually rebuild automations such as welcome series, abandoned cart emails, and re-engagement campaigns. Don’t assume they’ll transfer cleanly;
• test the logic of each trigger: Test entry conditions, delays, and branching to ensure everything works as it should.

Infrastructure and deliverability

Switching to a new service means changing your email sending infrastructure and effectively resetting your sender reputation, which is recorded in your email clients. Therefore, you may experience a drop in deliverability, an increase in being sent to spam, and having your IP addresses blocked.

What you need to do to minimize the negative impact:

• update your domain name system (DNS) records at least twice;
• set up SPF, DKIM, and DMARC on the new sending domain;
• update your authentication records;
• replace tracking domains or subdomains, if needed.

Once your old ESP account is no longer active, update or delete the DNS records confirming that the old service was an approved sender.

IP warming strategy

Switching to a new ESP means sending emails from new IP addresses. If you use dedicated IP addresses, ramp up sending gradually to avoid being listed as spam.

Here are some tips:

1. Spend 2-3 weeks gradually increasing the number of addresses for sending emails.
2. Prioritize engaged segments first and gradually expand sending to other segments.
3. Monitor bounce rates and sender reputation.

Once the warm-up is completed, you can begin sending to your contacts at your usual volume and frequency.

Data security risks and how to minimize them 

Switching ESPs or CRMs comes with real data security risks — from leaks during transfer to incomplete migration of critical info like user preferences or opt-in status. You could also risk insecure storage or transfer protocols or violating GDPR, CAN-SPAM, or other local privacy laws.

To minimize these risks, follow a structured, security-first approach:

• use secure, encrypted transfer methods (SFTP, HTTPS): These protocols protect your data while in transit, preventing interception or leaks during the migration process;
• ensure the new ESP/CRM is compliant and certified (SOC 2, ISO 27001): These certifications indicate that the provider follows strict data security and privacy standards, giving you confidence in their infrastructure and practices;
• set up access logs and perform regular permission audits: Track who has access to sensitive data and review permissions often to ensure that only the right team members can view or modify key information;
• involve your legal and data protection teams: They can help assess regulatory risks and ensure your migration process complies with GDPR, CAN-SPAM, and other applicable laws, reducing the risk of fines or legal issues later.

Taking these steps helps you protect customer data and stay compliant while switching platforms.

Post-migration checklist 

Once the transfer process is complete, check if you have installed and transferred everything correctly. Your goal is to validate that everything is working correctly, and that your new system is positioned to drive stronger engagement and results.

Follow this checklist, which contains the most essential points:

1. Is any subscriber data missing or improperly formatted? Check lists, tags, custom fields, and segments to ensure everything was imported correctly.
2. Do your email templates render correctly across all devices and email clients? Make sure the layout, design, and content are displayed as expected everywhere.
3. Are your automations working as intended? Test workflows to confirm that triggers, sequences, and conditions are firing correctly.
4. Have all outdated links been replaced? Review your emails, forms, and landing pages to ensure none point to your old ESP.
5. Are all integrations syncing data reliably? Test connections with CRMs, eCommerce tools, and other platforms to confirm that everything is functioning smoothly.
6. Have you run A/B tests to benchmark performance on the new platform? Try different subject lines, content blocks, and send times to check engagement and deliverability.
7. Are your emails reaching inboxes, not spam folders? Monitor deliverability, bounce rates, and sender reputation using reliable tools.

Tools and platforms to help with secure data transfer 

As you have already seen, when migrating from one platform to another, you perform different actions with your data. To make this process faster and more comfortable, use tools and services.

Recommended tools and services:

• data mapping and integration tools — Talend, Zapier — for integrations and data syncing;
• built-in migration services (offered by some enterprise ESPs like Salesforce, Iterable, etc.);
• secure network infrastructure and data transfer solutions — QuantumNova, BeamSec, Console Connect;
• SFTP/AWS Transfer/Google Cloud Storage — for secure file transfers;
• a contact verification tool like Validity BriteVerify, NeverBounce, or ZeroBounce for cleaning up your subscriber list;
• Mail Tester — for testing deliverability issues; 
• MxToolBox — for checking your DNS and your entire domain for errors and performing a complete analysis;
• Postmark DMARC or DMARCian for getting reports with insights, such as how many emails passed SPF and DKIM checks, and which sources are sending emails on your behalf.

Wrapping up

Switching ESPs or CRMs is a big move, but with the right planning, it doesn’t have to be risky. Think of it as more than just a technical task: it’s an opportunity to clean up your data, streamline your workflows, and strengthen your email marketing foundation. By protecting your data and treating migration as a strategic upgrade, you’re not just switching tools — you’re leveling up your entire process.