Inbox WM2003 "The message(s) could not be sent"

[cjelec]

OS: Windows Mobile 2003
App: Inbox
Device: Ipaq h6340

Hi,

I have a problem sending emails to my SMTP server. When I try to using the wifi connection (sync works fine) I get the following error messages:

The messages(s) could not be sent. Check that you have network coverage and that your account information is correct. Then try sending again.

Messages cannot be downloaded to your mobile device. Make sure you are connected and that your e-mail account settings are correct. Then, try to download messages again.

I have checked the log files for my POP3 and SMTP servers. Pop3 is working fine (connects gets mailbox...), but the pda connects to the SMTP server says HELO and QUITs straight away.

I have tried 'Outgoing e-mail server requires authentication', and tried setting the 'Domain' box.

Has anyone else had this problem, and does anyone know the solution?

Thanks