It used to be part of the email wizard, but that was removed when GMail started making itself hard to use with third-party "less secure" applications.
Here is the configuration details in the source code:
https://github.com/kovidgoyal/calibr...l.py#L193-L207
So you will need:
hostname: smtp.gmail.com
port: 587
username:
my_email_address@gmail.com
password: my_password
Then follow the directions here:
https://support.google.com/accounts/answer/6010255
And if you ever meet someone who works at Google, feel free to slap them.