The BoxTrapper feature filters spam from your inbox through verification. When an account with BoxTrapper enabled receives an email, BoxTrapper automatically sends a verification email in response. The sender must complete the verification process before the email can pass to your inbox. If the sender does not verify the email, the verification fails and BoxTrapper never clears the message for delivery. After a period of time, the system automatically deletes the spam.
BoxTrapper is designed to protect your inbox from spam. It requires all email senders, not on your approved list of addresses (your ‘whitelist’), to reply to a verification email before you can receive their mail. BoxTrapper returns a confirmation email to senders, who must reply before their email is delivered to your email address. A verified address is added to your whitelist. It is important to understand that even if BoxTrapper is enabled and automatic whitelisting is disabled, any email address you yourself send mail to will automatically be added to your whitelist without any other interaction. Since you are in effect interacting with that email address, BoxTrapper assumes you welcome interaction with this address and automatically whitelists the email address in question.