i had seen message in event viewer

The POP3 Service could not start because the POP3
authentication method is invalid for this Windows
configuration.

event id 1025

pls help me how to start pop3 service

[Vikram Gorla]

You will face this issue if you include your server to a domain after enabling POP3/Mailserver role.
POP3/Mailserver from Windows roles and install it again, it will fix the problem.

(The the actual issue is that the authentication mode would be Windows local mode before subscribing to active directory, it will change to active directory integrated mode later)

I know this post is old, but this answer will be useful if any new user faces same issue.

Cheers, Vikram