0x8004210A - The operation timed out.

Error Message - The operation timed out waiting for a response from the receiving (POP) server 0x8004210a. A time-out occurred while communicating with the server 0x800ccc19

 

Troubleshooting -

Disable email scanning in Anti-Virus program

Disable Firewall on system. If Outlook works with Firewall off refer them to the company of Firewall software.

Move any emails with large attachments on the web application to another folder and try popping the email again

Increase the server timeout

Run Telnet to see if there is a port being blocked