Have you change the Outgoing SMTP address to the one provided by your new ISP in MS Outlook? If so, check and see if the authentication setting is correct. Most ISP now requried authentication for using their SMTP server. You should be able to find those information from you new ISP web site support section. If you are using your own domain name (smtp.yourdomain.com) as your Outgoing SMTP server, check and make sure you are using your new ISP DNS servers. Thats all I can think of right now.
Ok, this is weird one!
I changed providers this week, and of course the static IPs changed for my router and W2k3 server, all internal PCs are under DHCP and working fine regarding Internet.
But, MS Outlook 2003 in all of the clients stopped working to send emails (yes only to send) I already have the clients authenticating with the SMTP server and what happens is that whatever email sent get stuck in the outbox UNLESS it is NOT HTML!
I have tried many different tests but I am right now running out of options! I also run the SCANPST tool without success. BTW even a test with an email account on the new ISP failed to send!
Thanks for ANY tip!
Task 'USER - Sending' reported error (0x800CCC0F) : 'The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP).'