I just set one up quite easily after reading that you can do this with Gmail's SMTP server from Adfrabe above.
I created a Gmail account and set it up to automatically forward all emails to my primary email address, so it is just like using my primary one.
Here is what the settings look like:
And here is instructions on how to setup email forwarding if you don't want to check your gmail account.
https://support.google.com/mail/answer/10957?hl=en