SMTP TLS , DMARC Record and some mailing related issues.

Hey Buddies ! I want to improve my mail delivery, please help me. In MXtoolbox, when I tested my Server's SMTP then it shows some issues - SMTP TLS Warning - Does not support TLS. SMTP Banner Check Reverse DNS does not match SMTP Banner SMTP Transaction Time 15.578 seconds - Not good! on Transaction Time and when I check MX of my hostname then it shows these errors - DMARC Record Published No DMARC Record found DMARC Policy Not Enabled. Please anyone tell me that how can I solve these issues and does these effects on mail delivery ?