In stead of writing an email, meet your boss personally.
Before you go, do a bit of homework , like highlighting your achievements, ( providing data will support as to why you should be given an hike.)
Most of important, meet the person in charge, when the concerned is in a good mood.
5th May 2018 From India, Mumbai
My boss is in US. I am in India.
So i can't. Plz help me to ask my boss about pay raise.
5th May 2018 From India, Hyderabad
I have been associated with ---the company name -- since __
The past year in the organisation has presented me opportunities in terms of learning and personal growth.
The learning has helped me to independently handle the following :
-- ( highlight profile as well as achievements ( mention word achievements )
I have been associated with the Company for a year and would request you to consider salary revision .
I am thankful for your guidance , without which it would have been difficult for me to achieve the above.
7th May 2018 From India, Mumbai