Addressing "Out of office" Vacation accounts

If there any standard, past proposal, effort or otherwise for detecting
auto-reply "vacation" or "out of office" messages?

I understand these two terms:  "vacation" or "out of office" (OOF) is
probably the closet  thing to implementing a partial filter solution.

I am thinking of adding some logic into our list server  but before I do I
would like to know the issues that I can come across.

Besides the obvious of automated disabling of list mail accounts false
positive), what other things would make this unreasonable?

Other questions:

What existing MUA products/software offer built OOF auto-reply features?

What existing list servers have features to support the disabling or making
inactive the list member on vacation?

Is there a past proposal, if not, why having there been a effort to write
one?  It seems like a reasonable consideration.  I would not mind writing a
draft if enough people are interested to pursue it, but I would not care if
anyone wrote it too. I would eagerly anticipate it and support it.

Thanks

--
Hector Santos, Santronics Software, Inc.
http://www.santronics.com