It's easy for us as we are in contact with many different customers around Europe every day so it is quite useful that they have this feature available now! We can send an invoice or order via email easily without having all of our files open at once which saves some time when you might want/need them right then but don't always know where your file will be stored yet - hence why I would like more space than one document per letter if possible just because sometimes things get moved about quickly within my department here too :).