The Case for Mapping Data Before Emails: Lessons from Three Major Migrations

Most brands plan an ESP migration backwards. They start by designing welcome flows, writing new subject lines, and debating pop-up forms. The logic feels right, after all, email is what the customer sees, but it’s usually why migrations overrun, or worse, stall.

The real work of moving to a new platform sits under the waterline. It’s the data: what events you collect, how you label them, and how they pass between systems. If that foundation isn’t in place, even the most polished email can’t send at the right time.

Put the journey before the technology

A reliable migration starts with mapping the customer journey in detail. For each stage; browse, purchase, replenish, return, you define the touchpoints you want to automate. Only then do you list the events and properties that power those touchpoints.

One CRM lead we spoke to described it neatly: “We actually started with our customer journey first… then the communication touchpoints… then we ended with a table of all the different events we’d need with the event properties we’d use for personalizing or segmenting each communication.”

That order matters. When you know which events you need, you can confirm whether your ecommerce platform and your ESP will talk to each other properly before you ever design an email.

Clean before you connect

Almost every brand underestimates how much damage untidy data can do. If you migrate before cleaning it, you import duplicates, bad naming conventions and conflicting opt-in statuses. Those issues show up later as double-sending, failed triggers and ugly reports.

As Riley from Loop Earplugs put it: “Clean your Shopify data before you turn the connection live. Getting it back out or cleaning it once it’s in two different places is a huge headache.”

Deduplicating profiles, agreeing on a single customer ID, and standardizing event names should happen before you flip the switch. It isn’t glamorous work, but it’s cheaper than troubleshooting in production.

Preserve your history

In the rush to streamline lists, many brands throw away valuable context. EasyToys’ team learned that the hard way.

Kevin, their analytics lead, warned: “Once it’s migrated away, you lose the historical opt-in track records… create an additional field to store the latest opt-in status or it gets overwritten.”

That piece of diligence, keeping the record of how and when consent was captured, saves headaches with compliance, segmentation and reporting later.

Start small, prove the plumbing

Before cloning every lifecycle flow, pick one high-value trigger such as abandoned basket and test it end-to-end in a staging environment. If the data moves cleanly from store to ESP, you’ll know the rest will follow. If it doesn’t, you’ll find out while the stakes are low.

The return on doing it right

Brands that invest time up-front in mapping journeys and cleaning data avoid the painful first quarter many suffer after a migration: broken flows, lost revenue, angry customers. They also save on license costs by keeping suppressed profiles in the database for analytics but excluding them from marketing sends.

The lesson is simple: emails should be the final sprint, not the starting gun. Build the foundation first and the creative work will actually reach the people it’s meant for.

Need help getting started? Feel free to DM me or schedule a call in my calendar.