Hello exim-users,
I am developing a small external tool for exim. If possible, I'd ask
you some comments. And if you are interested, I'd also ask some trial
and tests. If anyone comes up, I will open a new project on github and
make it public for anyone to use.
Here is a description about the tool.
- behaves like a pipe or a hook.
exim delivers a mail to localhost:10025, and this tool is listening on
that port.
- accepting, the tool connects to smtp.gmail.com:smtps via stunnel(1) so
that the tool can relay the SMTP session from exim.
- the tool handles MAIL FROM <sender@???> only.
+ obtain a refresh-token of the sender's from an external file (like
exim's passwd.client file).
+ obtain an access-token from accounts.google.com using the
refresh-token, client-id and client-secret.
client-id and client-secret are pre-obtained from Google API Console
(see below).
+ issue AUTH XOAUTH2 using the access-token and sender@???.
+ finally issue the original MAIL FROM <sender@???>.
+ all other smtp commands and replies in the session are not handled
and the tool just read/write between exim and smtp.gmail.com
transparently.
- unnecessary to allow "Less secure app access" for sender@???.
J. R. Okajima
