[Feature Request] Outgoing document emails: Reply-To header and a fixed signature

Description I use the Email action (single document and the bulk action, v3.3.1) to send bills and work orders to vendors and my accountant through an SMTP relay. Works well. Two small gaps, both of which could be plain config options rather than UI work. 1. Reply-To Messages go out with From = PAPERLESS_EMAIL_FROM and no Reply-To header. My From is a relay-only SMTP user, so anyone who hits Reply is writing to nobody. What I do now: the sending address is an alias on my own mailbox so replies land with me, and the display name carries a human name ("Owner via <system> <[email protected]>"). That works but it ties the sending identity to one mailbox and means a change at the mail provider for every instance or user. A PAPERLESS_EMAIL_REPLY_TO setting passed as reply_to on the EmailMessage would cover it in a line or two. #9626 asked for per-user From addresses; this is the simpler version of that. 2. A fixed signature / footer The Email dialog…