HTC 6800 wifi problem

[Charlie46]

I have set up a wireless network using Airport Express. Here's the problem:

1) Before adding security to the wireless network, I was able to both send and receive email - as well as browse using the HTC 6800.

2) After adding security, I can no longer send email, but I can still receive.

3) I can still send and receive email on my notebook.

4) If I turn off the security, the 6800 can see the wireless network, but it cannot connect to it.

5) There is no problem sending email if I switch to the cell lines.