I think this was the message you were trying to convey. Corrected version: In reference to your letter dated on …. Thank you for the proposal to restart discussing your recommendations. As for the August meeting, we propose having a video conference during the first 5 days of the month. We look forward to receiving your response as soon as it is possible. Best regards, (your name or company, etc.)

I haven't mentioned that the letter was written to contact an American company.

By the way, a colleague at work wrote that letter on my behalf.

Thanks Gary for your comment. Previously, we used to conduct a video conference call on monthly basis to discuss our customer's recommendations and opinions about our products, usually, during the first week of each month. But recently, we have stopped doing that activity. The company has suggested to start having those video conferences again starting from next August. That is the main theme of that letter. Thanks.

The meaning isn't always clear, e.g. what does 'as we used to do before' mean specifically? That isn't very formal, so needs changing to fit the tone of the rest of it, and to do that, we ideally need to know more of the context. It would also help to know who you are writing to, in terms of the correct level of formality. To me, the language is a little over-formal in a western context, so it would take quite a bit of work to rewrite. In other countries, that level of formality may be appropriate.