Contact "display as" field problem

I am using emclient v6…and imported email, etc from an outlook pst file.  Everything worked well except that in CONTACTS, the “display as” field which was the person’s name in my Outlook file is now the email address.  so when I send an email the TO shows eg as

joe@yahoo.com (joe@yahoo.com) instead of Joe Smith (joe@yahoo.com)

Is there any way of changing ALL the “display as” fields back to the person’s name without doing it one by one!

Thanks in advance

FranO