This article describes the process to recover a forgotten email and/or username associated to an account in the MySonicWall.com portal.
Here's how to recover a forgotten email and/or username on MySonicWall.com:

a. I have a registered serial number.

c. I have a few emails thats might work.
I'm not a robot" reCAPTCHA and click Continue.

NOTE: If you have also forgotten the password for your account, click on the link below to learn how to recover your password:
https://www.sonicwall.com/en-us/support/knowledge-base/170505949268101