COMMAND

    Outlook

SYSTEMS AFFECTED

    Microsoft Outlook (Express)

PROBLEM

    Matthew J. Brown found following.  Recently he had been  receiving
    calls from customers not being able to check their e-mail  because
    Outlook/Outlook Express says to check their "Memory and Diskspace"
    (or something  along those  lines..).   He began  looking at their
    /var/mail/ mailbox,  and noticed  a similarity  with all  of them.
    They  had  receieved  some  spam  which  had  left  the "BCC:" and
    "Reply-to:" headers blank.

    So  Matthew  attempted  to  reproduce  the  error,  and it worked.
    Outlook  Express  wouldn't  retreive  any  e-mail, if there was an
    e-mail that had those two feilds blank!

    According to Travis Ogdon this is also true for all messages  with
    the following invalid headers:

        Return-Path: <>
        From: <>

    Whenever we see SPAM like  this coming in we must  actually remove
    it  from  our  users  mailboxes  in  order for them to check their
    mail.  Matthew J. Brown tried it on Outlook 97 8.02.4212, and it
    actually crashed Outlook.

SOLUTION

    5.x build seems to be OK, while 8.x is horror story.