We tend to track business communication by the companies we do business with, not by individual contacts at the business (who may leave the company or change positions frequently).  When I get an important email from or about a client I want to be able to attach it to both the client record and the contact at that client from Outlook.

The notes module already works very well, in that I can write a note for a contact, and it will also be available under the parent account.  This is great, except it means I need to login to Zoho, search for the contact, and copy the note from Outlook into the contact record in Zoho.

When I attach an email I can do it all within Outlook, which is much more convenient...but then the email can easily be lost if I have a hundred contacts at a company and don't remember which one I was communicating with a year later when I need to find the communication.  It's telling that it is almost always easier to find an old communication in Outlook then it is in Zoho.

*Alternatively, if adding emails to accounts is not possible, perhaps you can add the ability to upload an email from Outlook as a note instead of an email?  This would have the added benefit of the content being searchable.