Compose eMail - previously used names

Compose eMail - previously used names

On my copy of ZOHO when I type in the opening characters of a name/email address in the 'To' section choices come up based on what I have used before. This makes filling in correct email addresses faster and more accurate. ZOHO has been installed on a colleague's pc but this feature does not work - she has to type in email addresses in full. It is not the Contact area because none of the email addresses I normally use are in Contacts and the same applies to my colleague.

There must be a setting somewhere to fix this - can someone please advise.