&gt; Not so long ago a user signed up to their site using my email address (never figured out why).<p>If they used legit billing information, with a name other than yours, it was probably a legitimate typo of the email address while signing up, using copy-paste to avoid typing the email address a second time.  They probably haven&#x27;t yet realized they aren&#x27;t getting emails for their account.<p>Someone (or two people with the same name) has signed up for a Hertz car rental account and a trash removal service account using a name that could reasonably be mapped to my gmail username.  I presume they either have &lt;my_username&gt;&lt;2&#x2F;year&#x2F;other_number&gt;@gmail.com or &lt;my_username&gt;@&lt;some_other_provider&gt;.