What the integration covers
- Transactional email only: order confirmations, quote requests and status changes go through SendGrid, kept separate from bulk newsletter sending.
- Single API key: no per-module configuration, the modules that send messages do not know or care which provider is behind them.
- No code change to switch: SendGrid sits alongside SMTP and Amazon SES on the same provider list; picking one is a settings change.
Why transactional and bulk are split
Bulk sending runs on its own channel (SES SMTP, Mailgun or another relay), independent of transactional mail. That separation means a newsletter campaign spike never risks delaying an order confirmation, and you can turn off the whole newsletter module if you use an external mailing platform without touching transactional delivery at all.