Mac Outlook Express 5.x Error -3216

• Firstly, we need to check that the modem is dialling out correctly. 
• Go to Apple > Control Panels > Remote Access

• Click Connect

• If the modem fails to dial out, it will almost certainly come up with the following error:

• If this is the case, then follow steps in this document: How To Resolve 'Port Already Open'

If the modem does dial out and you are able to connect, the problem can be more difficult to resolve.

1. Quit Outlook Express.
2. Dump Mac HD > System Folder > MacTCP DNR
3. Dump Mac HD > System Folder > Preferences > Outlook Express Preferences
4. Reboot
5. Establish a dial-up connection and launch Internet Explorer 5 (this problem only seems to happen when Internet Explorer 5 is installed.)
6. Go to Edit > Preferences > Network > Site Passwords (below) and delete all items listed on the right of the screen, then click OK.
7. Make sure that Internet Explorer 5 is capable of bringing up webpages, then launch Outlook Express and click Send & Receive.

NOTE: Error -3216 occurs only in Outlook Express 5.   Unfortunately, the message that is displayed with the error ("filename already in use") does not really give a good description of what has actually gone wrong.   The error implies one of two things.  Either there was no dial-up attempt and so you are not connected or you are connected but the connection is not valid.  That information on its own doesn't seem to be of any use, but from here it should be fairly simple to find out where exactly the problem lies.  The fix above should, in most cases, be sufficient to resolve this problem.  However, there are occasions where it can be difficult to provide a permanent resolution.  This is due to a known bug that is present in Outlook Express 5. 

NOTE: Error -3216 is officially caused because Outlook Express 5 is unable to see the IP address of the Mac it is running on.  As such, Outlook Express can think that the Mac is offline when in fact it is already connected to the Internet.  If this is indeed the case, then you may end up being forced to launch Internet Explorer first, bring up a web page, then launch Outlook Express.