Computer Help and Support

Too many to list.

One may have had your phone number in its stolen data. I recall various breaches at ATT and Verizon.

Many companies use your email address or phone number as logins. As a techie, I can’t begin to tell you how dumb as a brick this is.

And as others have noted, some spray-dial or email.

Worse, some companies you deal with sell your data to data aggregators.

Just don’t open anything you don’t recognize, and/or mark it as spam or junk and delete.