ACT! is normally geared towards keeping all users and stations in synchrony. But you may want to synchronize with certain clients, while keeping them separate from each other. Or you may have several different projects that require distinctly different ACT! databases.
If you are in the wrong file, you may synchronize an email sync packet in to the wrong database and it will be quite a mess to sort and separate the records out.
In the ACT! Knowledge Base it says: "synchronization of more than one ACT! Database from a single computer is not supported. "
If you only need to synchronize one way, from the branch offices to the main offices, that makes it easy. You can set up the different databases to synchronize through different email addresses to different computers on the network at the main office. In File, Administration, Define Users, remove the ability to synchronize for all users, except for the person who uses each specific workstation. So you can sync from one "upwards" to two or more at the headquarters. Use different machines or virtual machines at the headquarters.
You can set up Groups to synchronize with, but there is the possibility that an error could occur where contacts are sent to a client that should not be. Or if you want Notes to be separate, a different technique must be used.
You can set up multiple databases, and synchronize one on one with them. You can use Outlook to distinguish synchronization emails coming from certain clients. Each client should have a folder, and the Outlook Rules should be set up so that incoming email from a client goes in to the appropriate folder. You will need to move the email from one client's folder in to the main Outlook Inbox from which ACT! finds the synchronization email.
An easy way to keep them separate is to have a separate computer for each database. Computer 1 would synchronize Database A, and Computer 2 would synchronize Database B, Computer 3 would synchronize Database C, etc. This is the safest way, if you're a bit worried about the possibility of synchronizing the wrong databases. But it may be more expensive to have separate machines.
ACT! looks to an email program's In box to find the synchronization emails. If you need to use one computer, you could use 3 or 4 separate Inboxes for the separate email client programs:
ACT! Internet Mail
Microsoft Outlook
Microsoft Outlook Express
Eudora