Socket error #10053: software caused connection abort

Hello,

Another client today gets the following error: "Socket error #10053:
software caused connection abort" when sending an e-mail with IdSMTP
version 10.
She also got an installation menu of MS Office 2000 to insert the MS
CD-ROM when trying to send an e-mail with our Delphi app. After
inserting the CD-ROM and installing something of MS Office 2000 this
pop-up window did not come up again.

The same application works fine on other locations.

What is going wrong here ?

Thanks,
Hubert