Outlook 2003 and DoS

[Anteaus]

Had a situation yesterday where a SMTP mailserver was being DoS'd by a
client.

Culprit was an Outlook 2003 desktop, which was trying to send a number of
oversize attachments.

The mailserver has an attachment-size limit set, and quota on the mailbox,and
it seems that Outlook does not recognise this situation, but instead keeps
hammering the server with a continuous series of send attempts.

I'm not hopeful of any fix, but just thought I'd mention it.

 

[Roady [MVP]]

Securing a server isn't up to a client application.

 

[Diane Poremsky [MVP]]

What error code does the server give outlook when it refuses to accept the
message? Does the server NDR the oversized message? An error code should
stop the current attempt - and if it generates an NDR, all future attempts.
But if the server doesn't tell outlook (or the user in the form of a
warning email) how is either to know its too large?

(There won't be "a fix" to outlook.)









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