I'm in the process of migrating our mail from Exch5.5/NT4 ->RedHat/Scalix, to facilitate this I had to upgrade our mail client from Outlook 97 -> 2k. After upgrade outgoing attachments are not being received by recipients unless they're connecting via a browser.

i.e. tahir@my_yahoo_account shows attachments if I connect via the web, but the same message on my local mail client (thunderbird) shows no attachments.

Any clues appreciated.