Adjust Email HTML code so it works across all Email Clients

I have HTML code for a newsletter however, it doesn't display uniformly across different email clients. For example, it looks perfect in Hotmail but looks terrible in GMail. The biggest problem is the images. The coding is responsive so that it displays in mobile devices and as far as I know, that part of it is working however, if changes to the code this will need to be rechecked. I am looking for an experienced email html coder who can - 1. Review the code 2. Tweak the code to make it uniform across different email clients 3. Check to ensure the email also works on mobile devices The email clients that I need the email to work correctly in are - 1. Hotmail 2. Gmail 3. Yahoo Mail 4. Outlook 2003, 2007 and 2010. 5. Thunderbird The email has some unique tags in the html specifically for the email software that I use however, these are not affecting the email displaying across the different clients. The code is attached to this project so you can evaluate the amount of work required and bid accordingly.