I received an email today thanking me for registering to supportassist which included my phone number I had entered supposedly upon registration.

I'm pretty sure I registered over 2 years ago .

Email was: 

SupportAssist_NoReply@dell.com

Details below.

Congrats! Your installation and registration of SupportAssist is complete.

It named my phone number ,chosen language .

Not asking for any subscription fee or anything ?