use DANE when sending mail: if the recipient MX has a DANE TLSA record in DNS then Postfix will necessarily encrypt the mail in transport

This commit is contained in:
Joshua Tauberer 2014-06-19 01:58:14 +00:00
parent 95e61bc110
commit 782ad04b10
1 changed files with 9 additions and 2 deletions

View File

@ -59,9 +59,16 @@ tools/editconf.py /etc/postfix/main.cf \
smtpd_tls_key_file=$STORAGE_ROOT/ssl/ssl_private_key.pem \
smtpd_tls_received_header=yes
# When connecting to remote SMTP servers, prefer TLS.
# When connecting to remote SMTP servers, prefer TLS and use DANE if available.
# Postfix queries for the TLSA record on the destination MX host. If no TLSA records are found,
# then opportunistic TLS is used. Otherwise the server certificate must match the TLSA records
# or else the mail bounces. TLSA also requires DNSSEC on the MX host. Postfix doesn't do DNSSEC
# itself but assumes the system's nameserver does and reports DNSSEC status. Thus this also
# relies on our local bind9 server being present and smtp_dns_support_level being set to dnssec
# to use it.
tools/editconf.py /etc/postfix/main.cf \
smtp_tls_security_level=may \
smtp_tls_security_level=dane \
smtp_dns_support_level=dnssec \
smtp_tls_loglevel=2
# Who can send outbound mail?