Incoming mail is automatically linked based on the sending e-mail address:
If the address is recognized, and it is just located once in the database, then the message is linked to that user.
If the address is recognized, but it is located more then once in the database, the message is nog linked. However there are useful buttons to link the message manually.
This way we prevent that a message is linked to the wrong person.
Sent e-mail is automatically linked when te mail is sent directly from the file.
New mail from the e-mail overview isn't linked automatically.