This is apparently two separate issues. Same LFD issue on both servers, but only 1 had POP3 errors. So I looked at the other one first; the easy one with 1 error.
I forgot to set LF_ALERT_TO -- so that was user error. I found that one maybe 5 minutes after making this post. I always forget the LFD options are in the "CSF" configuration. But it's not just CSF in the config GUI.
However, my main server does NOT have anything set for LF_ALERT_TO, and all mail comes from [email protected] I did that so long ago (~1 year), that I just do not remember why it works. It sends email somehow, but I'm not sure where.
The POP3 issue appears to be separate.
Oct 29 21:40:39 servername lfd: Failed POP3 login from 184.108.40.206 - ignored