Direct Send Linux

I need an email delivery software. Not necessary mass sending software but the program must have the ability for mass delivery if an emergency need arises. All that is needed is a simple email sending program or script or software that can run on a Linux server system and be able to exchange email over DNS and not the SMTP protocol. There are several alternative software on Windows that I am experience with that sends email without any intermediate server. It simply uses DNS lookup for Mail exchange of the recipient server and manually delivers the email to the destination server. It exists and has been used on Windows. An email sending software that can exchange email directly without using the smtp protocol. It does not drop any single queue file for exchanging emails. It would be preferred if the program can be accessed via a browser. it could be any language. Also there must be personalization of email feature in the program.