ESP Switching & Migration

How to "change ships" without sinking. This section is a guide to migrating between ESPs (e.g., from Mailchimp to SendGrid). The #1 rule: you must warm up your new IPs and domains, as mailbox providers will treat you like a stranger.

11 questions in this topic

How do you migrate from one ESP to another safely? What are risks during ESP migrations? How to move sender reputation between ESPs? What is IP/domain warming after migration? What’s the best way to export/import suppression lists? How do you transfer templates, automations, and preferences? How do ESPs differ in bounce classification? How long should you keep both ESPs active during transition? What’s the difference between full migration and split delivery? How to update DNS records during migration? What are signs that migration hurt deliverability?

Questions about ESP Switching & Migration