IMail - AUTH ERROR ... - not in the table

Question/Problem: I'm getting a large number of the following in my System Monitor Log... 

20000523 162907 AUTH ERROR 202.72.149.76 0 - not in table Xae909c9b9892cfcbc960e23fe6

The source IP isn't always the same.

Answer/Solution: In IMail Administrator | localhost | Web Messaging Server enable this option: "Ignore source address in security check". In version 7.0 find services under IMail Administrator | localhost | Services.
Stop and restart the service.

This is caused by the use of dynamic IP addresses.

If you do not have Ignore Source Address checked the user would be kicked back to login. With it checked the ERR still shows in the log, but it is ignored.