Since we have not received any reply from you, we understand that you are not interested in this training and we are going to close your request as invalid.
I think your sentence is grammatically correct although it sounds a bit stiff and long-winded.
Thank you for you reply it is helpful for me!
I changed this sentence to - Since I have not received a response from you, I can assume that this request is not relevant and will be closed.
Hope it sounds polite.
Yes, that’s certainly better but the question is why you write this email in the first place. What exactly do you want to accomplish?
It is notification why I’m closing employees requests.
I wrote a message to them and haven’t received any reply, so I need to inform them why these requests will be closed.
Full message :Dear …,
Since I have not received a response from you, I can assume that this request is not relevant and will be closed.
Please feel free to reopen it or create a new ticket.
Actual training you may find in Training Plan
Why not simply write ‘Dear…, is your request still relevant or can I close it?’ If there is no response within 48 hours let the system close the request automatically. At the bottom of your message you can add the following line:
‘Please note that we will close your request if we don’t hear back from you within the next 48 hours. You will be able to re-open your request any time’.
Thank you Torsten, I will use your advise!
Sure, please check this: advise vs. advice