Whenever I try to send an email to a mailing list that I'm
subscribed, I get a reply telling that am I not authorized to send an
email to that mailing list, even if I send the email through the
configured account that's authorized to send to it. I believe the
problem is that, even though I send through that specific account, the
email still specifies the Return-Path and Sender headers as being from
my gmail account. Is there any way to change it so it points to the
right account?

Regards,
Thiago Souza