1) We have an old P133 (W98SE, IE6) that we use at home for browsing and EMail. Virus checker is BitDefender 9.

2) At work, we have OWA enabled for home users (W2003, Exchange 2003, Outlook 2003). Virus checker is McAfee Enterprise.

3) OWA worked fine from home until we set up a small Ethernet (3 PCs), based on a DLink G604T router. Afterwards, trying to send (or forward) anything via OWA resulted in:

a) the Send button graying out;

B) after a timeout, a one-word error message: Unknown.

4) We configured the DLink as a virtual SMTP server and re-booted. The problem went away.

5) Subsequently, we've had to re-configure the home network twice. The behaviour repeats; Send fails in WebMail until the P133 is configured as a virtual SMTP server.

We know OWA only uses HTTP and HTTPs. We think the issue is at the home end; specifically, with the router's firewall, the A/V software or some combination of the two.

Have you experienced a similar issue? If so, what was the fix? This has affected over a dozen users in our organisation since the start of the year, and we'd like to know what is going on. It is really bizarre to have to use a work-around involving SMTP, something OWA doesn't need, to fix this issue.

Try the good old elimination technique:

disable AV on the gateway and test

disable AV on PC and test

and so on..