Hi:
 
Binary attachments choke lots of e-mail systems.  There would be no
problem if everyone used the same computer platform, operating system, and
mail software.  Unfortunately, each platform and operating system uses its
own approach to handling (coding, unencoding, etc.) binary files.  Thus,
if there is a mismatch, the receiver's system may choke or freeze.  In
general, binary files sent in a mime format tend to cause fewer problems.
ASCII (text) files rarely cause any problems.
 
Also, systems using a shared server may run out of disk space - our
university system has several thousand users.  A chain mail message or
large influx of attachments on a given day will exceed the temporary
storage space.  In that case, all mail dumps, never to be seen again.
 
If you only get a few e-mail messages per day, the occassional attachment
usually is not a problem.
 
Cheers,  Jerry Bromenshenk