Maildrop is a replacement for your local mail delivery agent. I have configured maildrop (in my previous qmail installs) to filter all Spam related emails to go directly to the users Maildir/Spam folder. This no longer works. We now just need to install maildrop for qmail-scanner support. For more information, see http://www.courier-mta.org/maildrop.
Lets install maildrop:
# cd /usr/ports/mail/maildrop
# make install clean
Make sure the following option is checked:
[X] AUTH_VCHKPW popmail/vchkpw support
We need to run a quick fix for vdeliverquota
# ln -s /usr/local/bin/maildrop-deliverquota /usr/local/bin/deliverquota
At this point you have 2 choices for choosing how to setup your SSL Certificate. You can use the *free* Certbot walkthrough or you can convert your Apache Certificate to qmail. You can follow either link below.
Using Certbot Certs
Using Purchased Certs