Please check for any error and correctt them. THanks!!!

We have your letter dated August 17; concerning alternative dates to take discover disposition of the plaintiff and the defendant of this case.
We suggest that the disposition be scheduled 1:30 p.m. at your office on September 7, September 9, September 21, or September 23. We understand that you will provide the court reporter.
Please advise us, which of the above dates will suit your schedule. We will then contact our client and arrange for him to be present to give his discovery deposition at the mutual agreed upon date and time.

Not a semicolon in the first sentence because the 2nd half is not a complete sentence.

In the 2nd paragraph, no comma before which. Instead of "mutual" which is adjective, mutually, the adverb.

Sra