The short answer
A subscriber list is more than a column of email addresses. Status, preferences, acquisition history and automation position affect what each person should receive next. Before moving platforms, build a mapping for that context and test it with a small sample. A successful import count is only the first checkpoint.
Inventory the audience and its states
Export or otherwise record the fields you depend on, along with what each means. Include subscription status, tags, custom fields, language and preference choices. Identify where subscription evidence is held and how to retain it. Do not convert suppressed, unsubscribed or bounced contacts into active subscribers merely because the new platform accepts the file.
List every signup route: embedded forms, landing pages, checkout integrations and manually entered contacts. A forgotten old form can keep adding people to the previous system after the team thinks the migration is complete.
Map segments and automations explicitly
A tag in one product may not behave like a segment in another. Write the rule in plain language before rebuilding it: for example, subscribed readers who selected a particular topic and have not received the welcome sequence. Check how blank values, dates and multiple selections are interpreted.
For each active automation, decide what happens to people already inside it. Restarting everybody at step one can duplicate welcome messages or offers. Keep an exported position record where available, or define a conservative manual transition when positions cannot be imported.
Rehearse with a small, varied sample
Use test contacts representing different states: a new subscriber, a long-standing subscriber, an unsubscribed contact, a person with multiple interests and someone with missing fields. Import them into the destination and inspect the resulting records individually.
Send a test campaign and trigger the welcome path. Click the preference and unsubscribe links, then confirm the state changes inside the platform. Check the sender name, reply address, footer, tracked links and mobile rendering. This is a recommended rehearsal, not a claim that PerkDock measured any vendor’s deliverability.
Treat domains and paid access as separate workstreams
Follow the new vendor’s current instructions for sender-domain configuration and verification. Keep an inventory of the DNS records being changed and their purpose. Verify the final configuration in the product rather than assuming a saved DNS edit means the sending setup is complete.
If readers pay for access, inspect the payment and entitlement migration separately. A contact import does not itself move subscriptions, billing agreements, historical invoices or access permissions. Obtain the vendor’s supported migration procedure and confirm who owns each step before announcing a change.
Cut over deliberately and reconcile
Pause overlapping campaigns and schedule a clear cutover. Replace all signup forms and integrations, move the final changes, and compare source and destination counts by status rather than only the grand total. Keep the previous system available for reference until the reconciliation passes.
Make the first campaign intentionally narrow enough to investigate problems. Monitor unexpected bounces, missing personalization, duplicate messages and replies from confused readers. Do not promise a particular inbox placement from the migration alone; audience history, configuration and sending behavior all deserve investigation. Record what was moved, what could not be preserved and where the retained archive lives.
Sources & methodology
This article is an editorial analysis of official documentation, not an independent performance benchmark. Plan details and availability can change. Check the linked sources before purchasing.
