You'll see the following error message in H&R Block’s 2018 tax software if you entered an invalid email address when registering for CRA’s online mail service on the CRA questions page:
The email you entered doesn't seem to be valid. Please ensure you entered the correct email in the right format. [error code: 183]
How do I fix this?
To correct this error, return to the CRA questions page and make sure your email address is correct entered in the right format (example: firstname.lastname@example.org). You can find the CRA questions page under the REQUIRED icon on the PREPARE tab.