Migrate Your Email Platform With an AI Agent, Step by Step

Hand the move to an AI agent: custom fields, contacts and every unsubscribe, templates with rewritten merge tags, and automations rebuilt as sequences. Here's the order it works in and what you check at each step.

The Pombo team ·

You decided to leave your current email tool months ago. The export is easy; it's everything after it that keeps the move on the backlog: recreating custom fields, carrying the unsubscribes across, rewriting every merge tag, rebuilding each automation by hand. You can migrate your email platform with an AI agent instead, and hand that work over while the decisions stay with you.

This is for founders and small teams switching to Pombo who would rather delegate the move than do it by hand. It covers what the agent does, in what order, what you check, and what stays your call.

How to migrate your email platform with an AI agent

A migration is data transfer plus a careful cutover. In Pombo, an AI agent connected over MCP handles the data side of an AI email platform migration: creating custom fields, importing contacts, bringing templates across, and rebuilding automations as sequences. The cutover decisions stay with you. See what an agent can do.

The order matters, because each step depends on the one before:

  1. Custom fields
  2. Contacts
  3. Suppression: the unsubscribed, bounced and complained contacts
  4. Templates
  5. Sequences
  6. Cutover

Nothing sends during a migration. The agent builds; you decide when anything goes live. Sending in Pombo stays a click you make, and every send passes the sending gates first.

Before you start: connect the agent and give it read access

Connect your agent to Pombo. If you use Claude, Pombo's Agent Skills include one for migrations.

Then give the agent read access to the old account. A scoped API key is best, revoked when you're done; never your password. The alternative is a contact export: in Mailchimp, for example, contact exports and their CSVs stay available in your account for 30 days.[1] Whichever you use, make sure the contacts who unsubscribed come across along with everyone else.

A first request can be this plain:

Migrate our email from Mailchimp to Pombo. Here are the contact export and the unsubscribed export. Create the custom fields first, import contacts, carry every unsubscribe across, bring over the three templates we use most, and rebuild the welcome automation as a sequence. Leave everything in draft and tell me what you couldn't map.

Step 1: Custom fields before contacts

For every column in the export that isn't the email, a name or a status, the agent creates a matching custom field in Pombo first. This step comes first for a reason: if contacts are imported with a value for a field that doesn't exist yet, the value is dropped. Custom fields covers the field types.

What you check: the list of fields matches what you use. This is a good moment to drop fields nobody has looked at in a year.

Step 2: Contacts, then every unsubscribe

The agent imports your contacts with their fields. Then, as a separate import, it brings across everyone who unsubscribed, bounced or complained in the old tool, with that status.

This is the step not to skip. Those contacts stay in your Pombo audience with their status, and Pombo applies it by kind of email: an unsubscribed contact gets no marketing email but still gets transactional email such as receipts, while a bounced or complained address gets nothing at all. An agent can't work around suppression. Leaving the opt-outs behind would put people who already said no back on your marketing list, which risks complaints and your new sending domain's reputation. Suppression explains each status.

What you check: the contact count against the old tool, and that the unsubscribed count came across too.

Step 3: Templates, with the merge tags rewritten

For a design you want unchanged, the agent brings the existing HTML or MJML across as raw code and validates it, and you can preview each one. For the few templates you'll keep editing, it can rebuild them as editable blocks instead.

Merge tags need rewriting, not copying. In Mailchimp, a merge tag typed into content is wrapped in asterisks and pipes, like *|FNAME|*.[2] Pombo's equivalent is {{ first_name }}. A merge tag copied across unchanged would show up as literal text in someone's inbox, so the agent rewrites each one as it brings a template over.

What you check: open each preview. Look for any merge tag still in the old syntax, and any image still loading from the old platform's servers. Move those images into Pombo so they don't depend on an account you're about to close.

Step 4: Automations become sequences

The agent rebuilds each automation in the old tool as a Pombo sequence, matching the trigger, steps and delays where they map, and telling you about anything that doesn't. A Pombo sequence can start from an event your product sends, such as a signup, so review which events each sequence needs your backend to send. The events docs show the request.

The agent validates each sequence and leaves it in draft. Run it in simulation, which runs it against your real contacts without sending anything, to see how it would play out before it goes live.

What you check: each sequence's trigger and delays against the old automation, anything the agent said it couldn't map, and the simulation result.

Step 5: Cut over

Cutover is where the decisions are yours:

  1. Verify your sending domain if you haven't yet.
  2. Send yourself tests from two or three templates.
  3. Send a small real campaign to a test segment.
  4. Point your product's events at Pombo.
  5. Start the sequences.
  6. Stop the old tool's sends, and keep the old account read-only for a month in case you need to check something.

New Pombo accounts are reviewed before they can send. The review starts once your domain is verified and your mailing address is set, and you can do the first four steps of the migration while it happens. Sending gates has the detail.

How long does it take?

That depends on the size of your account, but your part is the same short list of checks: a look at the fields, two counts, a preview per template and a simulation per sequence. Start on your sending domain early, since sending waits on it.

If you'd rather do it by hand, the manual migration guide covers the same steps without an agent, and migrating off Mailchimp goes deeper on what breaks a list in a move.

Connect your agent

Connect your agent to Pombo, hand it your exports, and review what it builds before anything sends.

Frequently asked questions

What does an AI agent do in an email platform migration?

Connected to Pombo over MCP, it creates your custom fields, imports contacts, carries unsubscribed, bounced and complained contacts across, brings templates over with merge tags rewritten, and rebuilds automations as sequences left in draft.

Will my unsubscribes come across?

Yes, as a separate import with their status, so those contacts stay in your audience and are never emailed. Pombo honours unsubscribes and suppression on every send, and an agent can't work around them.

Does anything send during the migration?

No. The agent builds everything in draft. Sending stays a click you make, after you've checked the templates and simulated the sequences.

What do I need to give the agent?

Read access to your old account, ideally a scoped API key you revoke afterwards, or the contact and unsubscribed exports. Never your password.

Sources

  1. View or Export Your Contacts, Mailchimp
  2. Getting Started with Merge Tags, Mailchimp
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