Bring-your-own provider (BYO sending)
Also known as: BYO SMTP, Bring your own ESP
Definition
Bring-your-own provider is a model in which the marketing platform holds no sending infrastructure and instead dispatches every message through the customer's own SendGrid, Amazon SES, or similar account.
Why it matters
The consequences are commercial and technical. Commercially, delivery is billed at infrastructure rates — roughly $0.10 per 1,000 emails on SES — with no platform markup. Technically, sender reputation is isolated to your own domain and IPs rather than pooled across tenants.
The cost is setup effort and the need to manage provider-side concerns such as quota and sandbox status yourself.