Outgoing mail through Exchange Server with Pop3 connector
I have a pretty interesting problem. We currently use Windows SBS2003 with exchange server and a third party pop3 connector to pull down email from our web hosting company who provide us with email addresses at our domain name. Inside our office we have six users getting their mail off the exchange server and we have no problems sending or receiving mail inside the company. We can also send and receive mail from outside of the company with one major exception. We have four users outside of our office who have email addresses created web host but do not have user accounts setup on our Windows Server or Exchange Server. They access their mail from the web host directly though pop3 in Outlook. We can receive mail from them without any problems but we cannot send mail out to them. Everything we try to send out to them immediately comes back as undeliverable with the following message:
Your message did not reach some or all of the intended recipients.
Sent: 10/4/2004 4:46 PM
The following recipient(s) could not be reached:
email@example.com on 10/4/2004 4:45 PM
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
I am baffled by this and am in no way an expert in any of this! Any help would be much appreciated!