- _submission._tcp${suffix} SRV 0 1 587 smtp.immae.eu.
- _imap._tcp${suffix} SRV 0 1 143 imap.immae.eu.
- _imaps._tcp${suffix} SRV 0 1 993 imap.immae.eu.
- _pop3._tcp${suffix} SRV 10 1 110 pop3.immae.eu.
- _pop3s._tcp${suffix} SRV 10 1 995 pop3.immae.eu.
- _sieve._tcp${suffix} SRV 0 1 4190 imap.immae.eu.
+ _submission._tcp${suffix} SRV 0 1 587 smtp.immae.eu.
+ _submissions._tcp${suffix} SRV 0 1 465 smtp.immae.eu.
+ _imap._tcp${suffix} SRV 0 1 143 imap.immae.eu.
+ _imaps._tcp${suffix} SRV 0 1 993 imap.immae.eu.
+ _pop3._tcp${suffix} SRV 10 1 110 pop3.immae.eu.
+ _pop3s._tcp${suffix} SRV 10 1 995 pop3.immae.eu.
+ _sieve._tcp${suffix} SRV 0 1 4190 imap.immae.eu.
+
+ ; MTA-STS
+ ; https://blog.delouw.ch/2018/12/16/using-mta-sts-to-enhance-email-transport-security-and-privacy/
+ ; https://support.google.com/a/answer/9261504
+ _mta-sts${suffix} IN TXT "v=STSv1;id=20190630054629Z"
+ _smtp._tls${suffix} IN TXT "v=TLSRPTv1;rua=mailto:postmaster+mta-sts@immae.eu"
+ mta-sts${suffix} IN A ${config.myEnv.servers.eldiron.ips.main.ip4}
+ ${builtins.concatStringsSep "\n" (map (i: "mta-sts${suffix} IN AAAA ${i}") config.myEnv.servers.eldiron.ips.main.ip6)}