We have a server that uses POP3 authentication on the SMTP server. However, the process is not writing to the /etc/relayhosts file whenever an IP checks an account on the POP server. What service do I need to restart to get it to write to that file?

Thanks

What pop3 server what smtp server. What popbeforerelay program. Etc. etc.

What you are saying now is the same as:
My car won't start, what is wrong?