I should be able to integrate your MYOB accounting software with Constant contact.
Constant contact has a good API, which I would send post/get requests to from your software.
I will not ask for a fee unless the integration is done successfully and will offer future bug support for the code that I write.
Give me more information about exactly what you want to do with Constant contact and how it should interact with your accounting software, and I will come up with a plan to make it happen.