According to Matthias Scheler:
> 
> I agree that we need a smart way to use another mailer than "sendmail".
> But IMHO overwriting symlinks in "/usr/sbin" is no clean solution. There
> should be some kind of wrapper which gets the real mailer binary's path
> from a configuration file.
> 
In my humble opinion, I think any approach that disguises the real 
mailer behind "/usr/sbin/sendmail" is flawed.  If software does not 
include itself a mechanism to use an alternative "transport" then one 
would assume it _requires_ the real thing.  I can't think of any 
package that does not allow one to specify the mailer at the very least 
as a compile-time option, in many cases it is a run-time parameter.

Of course, we should by rights have /usr/libexec/ nicknames for 
sendmail in this context, although the scope of such a change could be 
quite vast.  Possibly dicussion on this topic may be more productive.

++L