Hello Roshan.
Just a quick introduction about me - I've 4 years of experience as a Web developer. I don't only code but I teach coding ( JQuery, PHP, MySQL, Wordpress etc) to others on my popular blog http://youhack.me.
Can you provide me with more details about the email marketing app you're using? Also are you using a third-party app or your own custom-developed API?
Looking forward to work with you on this project.
Regards,
Hyder