Move between sending providers
Shift traffic between MTAs or ESPs while preserving authentication and reputation.
- Difficulty:
- Advanced
- Prerequisites:
- Auth plan for the destination, IP/domain strategy
- Last updated:
- 2026-07-15
- Author:
- empire
Objective
Migrate sending infrastructure
Move sending to a new ESP or provider without breaking authentication.
Starting state
Two sending platforms available; traffic still on the source
Prerequisites
- Auth plan for the destination
- IP/domain strategy
Estimated time
2–4 hours
Difficulty
advanced
Required access
- Both platforms
- DNS
- monitoring
Inputs
- Source platform
- Destination platform
- Traffic split plan
Step-by-step instructions
- Mirror identity on the destinationPublish SPF/DKIM paths and align From domains before moving volume.
- Shift engaged slices firstMove low-risk cohorts and compare acceptance and placement.
- Complete cutoverRaise destination share only after metrics hold; then retire source credentials.
Verification
- Destination auth and placement match or beat the source
Common mistakes
- Big-bang cutover without parallel validation
- Keep source capacity warm as failover?
Rollback / recovery
- Pin traffic back to the source platform
Expected outcome
Production sending runs on the destination with stable delivery.
When to escalate
- Sustained blocks unique to the destination path