The following are settings when using Sendmail for mail delivery. When using Sendgrid, enter your Sendgrid email address as your Default Email Address.
Delivery Method: SMTP
SMTP Authentication Required? Yes
SMTP Port: 587
SMTP Character Set: utf-8
SMTP Security: TLS
SMTP Host: smtp.sendgrid.net
SMTP Username: apikey <- Just like this.. use the word “apikey”. See the image below.
SMTP Password: [actual api key here]