w3m-goto-mailto-url doesn't recognize vm-user-agent (non-member post)

[Andrew Scott <ascott@xxxxxxxxxxxxxxxxxxx>]

Thank you for a wonderful emacs-w3m product

I am a longtime user of the add-on View Mail elisp package by Kyle
Jones, which is very popular but not included with the default
Emacs-21.1 distribution.

When visiting a mailto within w3m e.g. 

mailto:ascott@sedona.intel.com (Andrew M. Scott)

w3m-goto-mailto-url generates the error message: 

You must specify valid `mail-user-agent'

For VM user's, mail-user-agent's value is vm-user-agent

I did find that in the Emacs 21.1 lisp area that simple.el
mentions only four values of mail-user-agent, none of which is
vm-user-agent.

Can w3m.el be modified to accept vm-user-agent as a valid
option for mail-user-agent?

Thank you,
Andy Scott


Platform:
Linux
Emacs-21.1
w3m_el-1.2.2 from http://emacs-w3m.namazu.org/
vm-7.00      from http://www.wonderworks.com/vm/download.html