After migrating several mailbox archives from SourceOne to Enterprise Vault (on-premises to on-premises), some end users reported that very old emails appear as unread, even though these messages had previously been opened.
The key point is to determine in what state the messages were archived.
• If SourceOne (S1) archived them as UNREAD, then Archive Shuttle (AS) will migrate them as UNREAD.
• If SourceOne (S1) archived them as READ, then Archive Shuttle (AS) will migrate them as READ.
The messages the end users reported may have been opened at some point however, they could have been archived in the UNREAD state before they were opened.
There is no setting in Archive Shuttle for SourceOne (S1) or Enterprise Vault (EV) to mark migrated messages as read, so Archive Shuttle does not modify this property during migration. This is only possible when migrating to Exchange Online.
