You cannot use a port other than 80, well not without some funky router making it appear to the exchange server that everything is still on port 80. Read MS KB article 325097 for more on this where they recommend only using the default port. I cant remember the exact details of the problem but from memory it was to do with OWA always replying on port 80 regardless of the incoming port from your firewall. I suppose you could map outgoing port 80 traffic from your exchange server back to the non-standard port at your firewall (ie the traffic from the server to the firewall is on port 80 in both directions) though I havent tried it myself. Charles Cresswell, IS Manager 020 7213 0728 The Association of Corporate Treasurers Ocean House 10/12 Little Trinity Lane London EC4V 2DJ tel: +44.(0)20 7213 9728 fax: +44.(0)20 7248 2591 www: http://www.treasurers.org Notice of Confidentiality This e-mail (and any attachments) is intended for the named addressee(s) only. It contains information that may be confidential. Unless you are the named addressee (or authorised to receive it for the addressee) you may not read, copy, use, or disclose it to anyone else. Unauthorised use, copying or disclosure is strictly prohibited and may be unlawful. If you have received this transmission in error, please notify the sender by telephone immediately 020 7213 0705 and delete the message from your e-mail system. The Association of Corporate Treasurers may monitor outgoing and incoming e-mails and other telecommunications on its e-mail and telecommunications systems. By replying to this e-mail you give your consent to such monitoring. The Association of Corporate Treasurers is a company limited by guarantee. It is registered in England at the above address, registration number 1445322. #ACT#