Jason Hendriks on "[Plugin: SendGrid] Which is better: SMTP or API? Is there a difference?"

@supergraham

The Web API has some advantages over SMTP:

• If your ISP blocks all outbound mail ports and your only option is HTTP.
• If there is high latency between your site and SendGrid, the Web API might be quicker since it does not require as many messages between the client and server.

https://sendgrid.com/docs/Integrate/index.html