I just stumbled upon an absolutely fantastic, couldn’t-be-simpler tutorial for git send-email. It really tickled the old-school, lo-fi geek in me to see git’s email workflow in action, and it only took a couple minutes—the developer’s equivalent of a cigarette break, really.

Just one snag: I couldn’t figure out how to set up credentials management (i.e., “passwordless” authentication) for git send-email, and my brain absolutely refused to postpone this problem until I actually needed a solution (which will probably be never).

Context

I use Pass to manage my passwords. I know every modern desktop has its own credentials manager (OS X Keychain, gnome-keyring, kwallet), but I prefer Pass for its simplicity, portability, and adherence to the UNIX philosophy (it stores passwords as GPG-encrypted plaintext files in your home directory). The one beef I have with it is its tragically generic name, which makes it a total nightmare to Google for.

Anyway, I already have git configured to use Pass for authentication to GitHub. It looks like this:

[credential "https://github.com"]
	helper = !pass git/rlue@github

where the output of pass git/rlue@github is:¹

username=rlue
password=password

But for the life of me, I couldn’t figure out how to extend this pattern to git send-email authentication, and the official docs for git-send-email and git-credential were not much help.

The solution

https://git-send-email.io already instructs you to configure git with your SMTP config:

[sendemail]
	smtpserver = smtp.example.com
	smtpuser = rlue@example.com
	smtpencryption = ssl
	smtpserverport = 465

With this in your .gitconfig, you can basically follow the same model as the “credential” section above; you just need to HTML-escape the special characters in the address of the server you’re authenticating against:²

[credential "smtp://rlue%40example.com@smtp.example.com%3a465"]
	helper = !pass git/rlue@example.com

where the output of pass git/rlue@example.com is:

password=password

(You only need the “password” line here since the “sendemail” section above already gives the username.)