Without more info about how you're actually sending the email (web?, smtp?, libraries?, etc), it's hard to give you a concise answer. That said, one of these three options should work:
1) If you're sending over HTTP with the web API
You can actually just add two extra parameters to your POST body,
replyto, and send them along with the normal
2) If you're sending over SMTP with the PHP library
The PHP helper library (found here) has two helper methods,
setFromName to help you with that.
$mail = new SendGrid\Mail(); $mail->addTo('email@example.com')-> setReplyTo('firstname.lastname@example.org')-> setFromName('John Doe')-> ...
3) If you're sending with SwiftMailer
SwiftMailer is a popular SMTP library for PHP. It has it's own helper methods from Reply to and From name. You can find more info in the docs (see