Question : Problem: Sending email from IPhone

I have setup IMAP on the exchange 2003 server and can receive mail without problems on the IPhone.  When connected at the office on the wireless network I can't send email from the phone.  I suspect it is an SMTP configuration issue.  I get the following message: There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
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When away from the office and on the Edge network I can both send and receive emails.  Any ideas?

Answer : Problem: Sending email from IPhone

Perhaps the IP address you are obtaining from your work network when you connect wirelessly is not allowed to relay mail through your Exchange Server's SMTP virtual server.  Some how you are being prevented from sending mail through the Exchange server.  Everyone else on the inside of your network is probably using Outlook and not needing to send mail via SMTP.  I would check this on the Exchange server.