Invalid and Dead Email Addresses
A member's account must always have a valid, working email address so the user can be contacted by other eBay members and by eBay. If a spam filter prevents messages from eBay or its members from reaching an account, the account is considered to have an invalid email address. Members need to take steps to ensure their account is valid and working.
Violations of this policy may result in a range of actions, including:
Limits on account privileges
Forfeiture of eBay fees on cancelled listings
Loss of PowerSeller status
Members who get an error message when they send a message to another member's email address are most likely contacting an invalid or non-working address. Members are encouraged to report this by using the Customer Support link at the bottom of this page, and including the error message in their report.
Why does eBay have this policy?
eBay's success is dependent on open communication between members as well as between eBay and its members. Members' valid, working email addresses are essential to that communication.