Re: time.el and display-time-mail-function

[Richard M. Stallman]

    This can be worked around in several ways (undefining the env var
    MAIL, setting display-time-mail-file to t, etc), but I see those as
    hacks around the problem of the "or".  Changing it to a "cond" seems
    to do the more correct thing.

In principle, the change you are asking for will make things more
flexible, since the user-defined function could check the standard
places too.

However, it would be an incompatible change, and I am not sure who
many users take advantage of the current code and would have to change
their init files.  WIthout pollinmg the users to find out how many, I
think it is better to keep the code unchanged, and you can use one of
the various workarounds.  For instance, you could set
display-time-mail-file to t.