Unregistration deletes your whole account with mailchuck. The emails that you already received remain in your bitmessage client. Please be careful, because someone else can then register the same email address.

To unregister, simply send a message from a an address associated with an existing account to BM-2cVMAHTRjZHCTPMue75XBK5Tco175DtJ9J:

Unregistering 1

You will receive a confirmation:

Unregistering 2