4 ms·

MTA-STS is nothing like SPF. SPF is a method to publish a policy on which senders are allowed to use your domain so send email. MTA-STS is a method to force M

by LeonM 8y ago

MTA-STS is nothing like SPF. SPF is a method to publish a policy on which senders are allowed to use your domain so send email. MTA-STS is a method to force MTA's to only use and accept TLS encrypted connections when handling email send from your domain. The MTA-STS resolver you linked to is used to implement MTA-STS capability in Postfix MTA. It's intended for MTA administrators. You don't use the resolver to setup MTA-STS for your own send email, for that you must setup a DNS record and a HTTPS enabled webserver.

megous 8y ago
> MTA-STS is a method to force MTA's to only use and accept TLS It's still advisory information, like SPF. The other end has to implement it.
- LeonM 8y ago
  That is correct. SPF, DKIM, DMARC, MTA-STS and TLS-RPT are all opt-in features for the receivers. One could say that email is the ultimate legacy product of the internet.