This is really harmless and probably not worth fixing.  You have a file
association stored in windows that tells windows that files ending in .dat
should be opened with Microsoft Comic Chat.  This is the same process that
windows uses to make sure .doc files are opened in Word, etc.  That is why
you see that icon.  Some email programs put the original email into an
attachment, and put the error message in the body of the email, when they
return as undelivered one of your messages.  Since your sent folder has the
undelivered email anyway, you can just erase the returned version after you
view the error message and take the appropriate corrective action to resend
the original in the sent folder.
DAT files were popular with application programs over ten years ago but are
rarely seen today so you shouldn't run into any more problems with the wrong
file association.  How to correct or remove a file association depends on
your version of windows.  Since this is a common complaint, there are lots
of articles on the web showing the procedure if it continues to bother you.
For Win98, click on My Computer, View, Folder Options,File Types, and scroll
until you see Microsoft Comic Chat, or DAT file.  Click Edit, and highlight
Open and click Edit. Here you can change the icon, or associate the file
type extension (.dat) with another program.  I use wordpad for .dat files,
although I rarely try to open them (for the reason above that the email in
my sent folder is easier to access.)
Tom Turak

-----Original Message-----
From: Beverly Caviness [mailto:[log in to unmask]]
Sent: Saturday, January 05, 2002 11:28 PM

Help -- my problem sometimes when I send an e-mail to several people it
comes back undelivered from one of them undelivered and there is an
attachment sometimes two. It has the icon of a program I once had and
removed from my computer "Microsoft comic chat"- this is followed by the
letters ATT00* a different number and .dat as ATT00145.dat.
I've searched my computer to remove all files with this icon, and run
searches.  But somewhere in there is something that makes this type of file
attach to e-mails I send then they come back undelivered.

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