Hope you and <xyz.com> are doing well in delighting customers by providing quality products with competitive rates in marketplace.
It has been wonderful journey of 3 years that we travelled together and developed business solutions using <technology name>.
Working on this complex emerging technology during this tenure has really increased our software development proficiency to next level in global competition. Your support has been phenomenon throughout all project phases from initiation to end. Thanks for contributing in our growth.
We are aiming to repeat the same success with our future customers who are working in this technology and platform.
While exploring prospect we have observed a business opportunity with <def.com> that operates in your region but belongs to different industry.
We are in conversation with them to understand the business requirements in alignment of our software development services. They have requested some feedback of our past successful delivery.
Hence, we would be highly obliged if you can attach your recommendation for us based on your experience in reply of this email so that we can attach same copy with our proposal to be submitted by 21st April 2018.
We trust that, your feedback will be our asset for professional and personal development.
We look forward to learn from you.