An email or text message acts as the notification that a transfer has occurred and provides instructions on depositing the money. The money is actually transferred over a secured network, and a security question ensures the money goes to the right person.
For security, always use a unique security question and answer for each individual recipient. Ensure the email or phone number of your recipient is correct and up to date. Remember, never put the answer to your security question in the message field when sending your e-transfer.