Respected Sir/ Madam,
I am ___________ (name) and I write this email with the utmost respect to inform you that I am working in your company as a ___________ (mention designation).
I feel happy to inform you that I have been working in this company for the past __________ (years) years and I am committed to my job with dedication. I have always offered my hard work and that has provided this company with top results. As time passed, a constant improvement can be observed in my performance, I believe that I am eligible for a promotion as I have not received any promotion for the last _________ (mention duration).
Respected, I have never kept any of my demands in front of the management and therefore, I write this email with the utmost respect and hope, in order to request you to kindly consider my promotion.
____________ (Contact details)