Can I bring my existing list?
Yes. There are three ways in, and one thing worth planning before you send.
Getting the data in
- CSV or TSV import for a one-time move. Include tags and custom data as columns and they come across with the subscriber.
- The Subscribers API for ongoing sync from your own system.
- Manually, for small numbers.
The subscriber documentation covers all three, including what the import expects your file to look like.
Coming from a specific platform
We have step-by-step guides for the common moves:
What does not come across
Engagement history. Opens and clicks from your old platform stay there, so engagement-based segments start empty and fill as people interact with mail you send from Broadcast. Plan for a short window where “opened in the last 30 days” matches nobody.
Bring your suppression list over separately. Hard bounces and complaints from your previous platform should go into suppressions before your first send, not after. Mailing addresses that already bounced elsewhere is the fastest way to damage a new sending domain.
Before the first send
You are sending from a new domain and a new IP, and mailbox providers have no history for either. Read the domain warm-up guide and start with your most engaged people rather than the whole list.
Confirm SPF, DKIM, and DMARC are green first. See fixing DNS authentication if they are not.
Large or unusual list? Ask before you import.
