If you have a lot of users and you want to control their email
signature, then signature template is what you need. With my module
res_users_signature you can create signature template and apply one
for your users.
A user can choose his signature template himself at Preference window (which is opened via top right hand menu).
Technically the module make minimal changes at user model. It just put new
signature field at
The module updates signature if there are changes at basic users
hr.employee). E.g. if a user
change his phone number, then his signature would be updated. Also,
you can update all signatures manually.
You can use base64-encoded images at signature template:
I've found, that some email clients doesn't show such images. In order
to fix it, the module overwrite
build_email function at
ir.mail_server model. The module make attachments from base64 images
at email body.