Explanation:
MAIL.BOX files and their content should be unique for every server. Having
a replica of a MAIL.BOX file on another server can cause unnecessary replication
activity and potential mail routing issues. Having a replicas of a MAIL.BOX
enabled for cluster replication between cluster mates may cause a high
rate of unnecessary replication activity and potential mail routing issues.
Recommendation:
Disable the MAIL.BOX settings in the clustered database directory (cldbdir.nsf).
Remove all but one replica of this mail.box file. Make sure that the MAIL.BOX
is empty before removing the file. Otherwise, you may destroy mail yet
to be routed.