Mercury POP3 Client errors

I just started using Mercury email server for our small company and it's working great, except I'm wondering about the logs. The statistics log shows network and password errors for each pop account it's checking. (about 26 accounts) It's not consistent except for the fact that the errors are there. It shows 2-7 errors in each category for each pop account. But everything IS working. We are running the modules for POP3 server, POP3 client, SMTP end-to-end client, SMTP server. Also - the statistics log shows 2 password errors per day on the local POP3 server but the POP3 server log shows no errors. ?? Any insight into this is greatly appreciated. Bill