Feature request: Domain email signature

For Usermin, there is already a signature feature built-in, though it is not domain-wide.

I've never done it system or domain-wide, so I had to do a little searching.

Wietse Venema (the author of Postfix, the default MTA in a Virtualmin system) has commented on the idea in the past, and brings up several pretty serious potential gotchas in doing so (because mail can be any of a number of formats, including some for which simply appending text to the end would be nonsensical).

But, there does appear to be a content filter designed specifically for this purpose, that might be worth giving a try:

http://www.karstenschulz.name/assets/en/mailsigger/mailsigger.html

Looks easy enough to setup, as it's like any other content filter. One thing to note is that in the example configuration mailsigger is only used for mail coming from a specific range of IP addresses, which may not be what you want (in a virtual hosting environment, outgoing mail can be received from anywhere, as long as the user authenticates). So, the complexity of the actual mailsigger configuration might be higher in such a case. I dunno. Never used it.

I would probably be pretty easy to write a Virtualmin plug-in to edit the signature mapping file in the UI.