what-is-mta

Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS

MTA-TLS & MTA-STS Explained: Secure Email Delivery 2026

Learn how MTA-TLS and MTA-STS secure email delivery. Reduce bounces, improve inbox placement, and verify your infrastructure with MailTester’s real-time.

Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS

How an MTA Signs Email with DKIM in 2026

Learn how an MTA signs email with DKIM—step by step, from key generation to header insertion. Improve deliverability and sender reputation with real-world.