The Internet Corporation for Assigned Names and Numbers (ICANN) requires the private contact information for all domains be stored in a publicly-accessible database.
Spammers and other bad actors routinely harvest contact information from this database en masse and use it to distribute spam to domain owners via email, phone and snail mail. Much of this spam consists of misleading come-ons and phony invoices trying to trick owners into transferring their domains to the spammer's control.
Many domain name registrars, including Signal, offer some type of privacy add-on to your domain registrations that keeps your contact information private. Your actual contact information is replaced by generic information, which still satisfies ICANN requirements.
The domain privacy system used by Signal maintains registrants' real email address on-file so users continue to receive legitimate information about the status of their registration. But it displays to the public a constantly changing substitute email address. So while those email addresses may still be harvested, sold and redistributed among Internet ne'er-do-wells, previous contact email addresses will no longer work as they're temporary.
Here's signalz.com's publicly-accessible contact data before and after applying domain privacy:
Signal is committed to reducing the amount of spam and misleading offers sent to our customers. If you're a current domain name customer, get in touch for details on Signal's domain privacy add-on.
And if you're shopping for a domain name, remember Signal is a full-service Internet marketing firm that can handle your domain name registration needs.