I just received an email from my registrar with the subject:
"Important Notice Regarding Your Domain Name(s)".
What do I need to do?
Every year, ICANN (the Internet Corporation for Assigned Names and Numbers) requires all accredited registrars (like Network Solutions, Go Daddy, etc.) to ask their domain registrants (that's you) to review domain name contact information for accuracy and make any changes necessary.
If your contact info is correct, then no further action is necessary. If your contact data is not accurate, following the instructions in the email to correct it.