[Mimedefang] Why'd this happen?

[Ashley M. Kirchner]

Jan 23 18:35:08 serpico sm-mta[17056]: h0O1Z6VP017056: 
from=<xxxxxxxxx at win.net>, size=74022, class=0, nrcpts=1, 
msgid=<3E308B1E.5A7C475E at win.net>, proto=SMTP, daemon=MTA, 
relay=nb-203.win.net [216.24.27.203]
Jan 23 18:35:10 serpico mimedefang-multiplexor: Slave 0 stderr: Out of 
memory! 
Jan 23 18:35:10 serpico mimedefang-multiplexor: Slave 0 ran out of 
memory -- possible DoS attack due to complex MIME?
Jan 23 18:35:10 serpico mimedefang[17057]: Error from multiplexor: ERR 
No response from slave
Jan 23 18:35:10 serpico sm-mta[17056]: h0O1Z6VP017056: Milter: data, 
reject=451 4.7.1 Please try again later

    This came from a legitimate user, sending to someone on our domain. 
 Is there something they're doing (perhaps not knowing) that I can tell 
them to change...anything?

-- 
W | I haven't lost my mind; it's backed up on tape somewhere.
  +--------------------------------------------------------------------
  Ashley M. Kirchner <mailto:ashley at pcraft.com>   .   303.442.6410 x130
  IT Director / SysAdmin / WebSmith             .     800.441.3873 x130
  Photo Craft Laboratories, Inc.            .     3550 Arapahoe Ave. #6
  http://www.pcraft.com ..... .  .    .       Boulder, CO 80303, U.S.A.