dovecot.conf

listen = *
login_access_sockets = tcpwrap

# auth
auth_verbose = yes
disable_plaintext_auth = no
auth_mechanisms = plain login
passdb {
  driver = passwd
}
userdb {
  driver = passwd
}

# SSL
ssl = yes
verbose_ssl = yes
ssl_cert = </usr/local/etc/letsencrypt/live/example.com/fullchain.pem
ssl_key = </usr/local/etc/letsencrypt/live/example.com/privkey.pem
ssl_dh=</usr/local/etc/dovecot/dh.pem
ssl_min_protocol = TLSv1

# mailboxes
mail_location = maildir:~/Maildir
namespace inbox {
  inbox = yes
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox SPAM {
    special_use = \Junk
  }
  mailbox Trash {
    special_use = \Trash
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
}

# protocols
protocols = imap pop3
protocol imap {
  mail_max_userip_connections = 20
}
protocol pop3 {
  mail_max_userip_connections = 10
}

# services
service imap-login {
  inet_listener imap {
    port = 143
  }
  inet_listener imaps {
    port = 993
    ssl = yes
  }
}
service pop3-login {
  inet_listener pop3 {
    port = 110
  }
  inet_listener pop3s {
    port = 995
    ssl = yes
  }
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    mode = 0666
    user = postfix
  }
}
service tcpwrap {
  unix_listener login/tcpwrap {
    mode = 0666
  }
}