This error indicates that the recipient MTA-STS policy MX does not support TLS. MTAs supporting an MTA-STS policy MUST have support for TLS 1.2 or higher, otherwise encryption will fail.
DMARC is the key to improving Email Deliverability!
Email is the key to your customer communication strategy. But, what is your email reputation?
Setting up and managing your DMARC configuration is the key to getting insight into your email delivery. MxToolbox is the key to understanding DMARC.
MxToolbox Delivery Center gives you:
- Who is sending phishing email purporting to be from your domain
- What is the reputation of your domains and delegated IPs
- Where other senders are and What their reputations are
- How your SPF, DKIM and DMARC setup is performing
- What on-going maintenance you need to maintain and improve your email deliverability
Learn More