I suggest to save the sent mail only in the Mail database and put a sorta of mail send request in another DB ( I.E. mailreq.box ) .
This DB will be processed from a task (i.e. mailreq, not the router) who copy it in the mail.box is some condition ...
Today when enable an archive criteria for a mail database we have only 2 options:
Restrictions such as quotas, attachments limits, and "user rules mail forwarding" -- all currently configured in Server Configuration documents, and therefore having a minimum granularity level of one server -- should be moved to Policy settings, since these are restrictions that apply to users, not to servers.
Currently with Policies they are applied based on OU or explicitly. Further, for archive policies, you can choose either a specific archive server, or choose to archive to the home mail server.
This is not flexible enough if you have many users in the same OU spread across 2 or more ...
Right now there is NO way to use an API or exposed program method to write an agent which will check or uncheck the replication advanced options which would prevent design and form updates.
This is useful when doing a slow progressive migration or upgrade from r5 to r7 in ...