The only things indexed for search are: message-id, subject, date (usually extracted from the Recieved: header), sender name (extracted from From: header), posting address (for example, gossip@mail-archive.com), archival message number, and message body. Every message is sorted and organized according to posting address.
The To: header is examined when sorting regular inbound mail and is a factor when deciding where it belongs. But the To: header is never indexed for search, never used during import, and there is no benefit for you to adjust it. A merged archive will have the same posting address for every message, with no memory about what life was like before the merge.
_______________________________________________ Gossip mailing list https://www.mail-archive.com/gossip@mail-archive.com https://www.mail-archive.com/cgi-bin/mailman/options/gossip