The Pi-hole® is a DNS sinkhole that protects your devices from unwanted content, without installing any client-side software.
maildrop is a replacement for your local mail delivery agent. maildrop reads a mail message from standard input, then delivers the message to your mailbox. maildrop knows how to deliver mail to mbox-style mailboxes, and maildirs. "maildir" is a mailbox format used by the Courier mail server and Qmail.
maildrop optionally reads instructions from a file, which describe how to filter incoming mail. These instructions can direct maildrop to deliver the message to an alternate mailbox, or forward it somewhere else. Unlike procmail, maildrop uses a structured filtering language.