What’s the difference between full migration and split delivery?

Full migration and split delivery are different strategies with different goals.

Full migration:

Move all sending from old ESP to new ESP

End state: one ESP handles everything

Simpler long-term management

Temporary parallel running during transition

Split delivery:

Permanently route different email types through different providers

Example: Transactional through SendGrid, marketing through Klaviyo

Each ESP optimized for its use case

Ongoing management of multiple platforms

Why choose split delivery:

Specialization: Different ESPs excel at different things (transactional speed vs marketing features)

Reputation isolation: Keep transactional separate from marketing to protect critical emails

Redundancy: Multiple providers reduce single-point-of-failure risk

Best-of-breed: Use best tool for each job rather than compromise on one platform

Why choose full migration:

Simplicity: One vendor, one dashboard, one integration

Data centralization: Complete subscriber view in one system

Cost efficiency: Often better pricing with consolidated volume

Reduced complexity: Fewer systems to manage and troubleshoot

Some organizations start with full migration planning and evolve to split delivery as needs become clearer.