How should that work? Emails are much more likely to be unique than names.

Em, maybe my explanation was not clear. OK let me try it this way.



For example:



I have contact "Test Person" in my address book with email 
"email@example.com". I recieve email from "Test Person 
<anotheremail@example.com>". I reply to it. Email is sent. New contact 
in address book is created and now we have two contacts with the same 
name but different email.



Basically what I want to achieve is that "anotheremail@example.com" 
would be added to the old contact, not the new one.

Huh?

Are the addresses when sending email from IMP (when saving recipients 
automatically is enabled) are edited acordingly? For example new email 
address is added to old contact if seconf object_email is detected? Or 
the new contact is created anyway?

This is already possible. Just add a second (or more) 'email2' => 
'object_email' to your sources.php.

Allow contacts to have more than one email address.