What sender certification programs exist (e.g., Validity Certification)?

Sender certification programs beyond CSA include Validity Certification (formerly Return Path Certification), which operates globally and is particularly influential with US based providers. Other regional programs exist for specific markets.

Validity offers tiered certification levels based on sender practices and volume. Higher tiers require stricter compliance and provide greater benefits. Their certification affects filtering at many major mailbox providers.

Some ESPs offer internal certification or preferred sender programs with similar goals. These vary in rigor and recognition. Established third party programs like CSA and Validity generally carry more weight with mailbox providers than ESP specific programs.