Courier with TLS connection

cat /etc/ssl.key/domain_de.key /etc/ssl.crt/domain_de.crt /etc/ssl.crt/domain_de.cabundle > /etc/ssl.crt/domain_de.pem
TLS_CERTFILE=/etc/ssl.crt/domain_de.pem
IMAPDSTARTTLS=YES
IMAP_TLS_REQUIRED=0