Reason for Error
When an email is attached to a record, there must be entity records in NetSuite that matches the sender/recipient of the email. CloudExtend Gmail tries to locate these records by matching the email addresses of the sender/recipient of the email with the entity records in NetSuite. If there's no entity found, CloudExtend Google Apps creates a contact record with the format "firstname.lastname company.com" and attaches the email with that contact as the sender/recipient. The creation of the contact record might fail if a custom/non-standard contact form is being used as default in the NetSuite account.
To remedy this, a contact record must be manually created in NetSuite that contains the email address of the sender/recipient.