Go to the ADMIN tab > PLUGINS > then select SMTP MAINTENANCE.
Click on the GREEN + button. (See image) to add a new mail server.
When you click on the GREEN + a dialogue box will appear. That is where you will fill out the credentials for the server and click Create.
Now you will be able to test your SMTP Account right away to make sure the credentials are correct and that it is running how it should be.
To do this you will click on the Envelope Icon.
Once the envelope is open it will display another window. There you will enter in your email address.
Once you've entered your email then click on ‘SEND TEST’. This is going to let you know whether it was successful or not. You will see the results by scrolling down to the bottom (see image).
Note: If it does NOT read "SUCCESSFUL", chances are there is something wrong with the credentials.
You will need to enable “Less Secure Apps” inside your Google settings.
Inside your admin console, go to Security, then turn on Less Secure Apps. https://myaccount.google.com/lesssecureapps
Google host: smtp.gmail.com
Host Name: smtp.sendgrid.net
Username: apikey (Not your actual API key- type in “apikey”)
From Email: the address associated with this SMTP Profile
password: API key from Sengrid