Dear Name
During your five months of employment with (name of the company) the management has informed you three times in their appraisal sessions that your performance is not up to the standards of your position and you had also been given areas where you have to show improvement.
We regret to say that you have not come up to our expectations and that your performance has been unsatisfactory. As per the policy of the company we are putting you back into retraining for one month and during this time we will be monitoring your performance. You will be monitored by the technical team as well as your immediate manager and the trainer. If there is any improvement we will think of taking you back to production or else the management has the Authority to relieve you of your services with immediate effect.
I would suggest you to take this one month seriously and put in your best effort as you are getting another chance to prove your work. If you have any doubts about this training or if you need any other help please feel free to approach me. I feel you are capable of achieving the target expected from you if you work hard.
All the best
(Signature of the Authorize)