It is important for employers to send an invite to an employee using the email address that they will use for accessing canuwork.  

If you invite an employee using one of their email addresses, but they then signup on canuwork using a different email address, they will not receive the invite (in Profile => Pending), and therefore will not be able to 'join' you team to receive future work requests.

Employees should always provide the employer with their preferred email address which they will also use to signup on canuwork.

Employees can also change their username (email) after signing up in the Settings screen under 'Update Account Settings'.