Yes, two responses (in both English and French) are accepted by the service and Interac will reply to these messages. Remember that text messages are limited to very few characters and therefore do not contain detailed information.
A HELP reply to short code 100001 will provide you with the address of this website, and instructions to type the link received in your notification into any browser.
To permanently stop all text message notifications from Interac e-Transfer, reply to any of the texts with the message STOP (or text STOP to 100001). Once stopped, text message notifications cannot be re-started.
Standard text messaging charges apply.