How to Send an SMTP Email | Twilio - SendGrid
docs.sendgrid.com › getting-started-smtpSendGrid provides an SMTP service that allows you to deliver your email via our servers instead of your own client or server. This means you can count on SendGrid's delivery at scale for your SMTP needs. SendGrid’s SMTP API also allows you to specify custom email handling instructions using a JSON encoded list called the X-SMTPAPI header. The X-SMTPAPI header is parsed by SendGrid to modify your message in the ways you specify.