I want someone to check the following letter and tell me about any grammatical errors in it.
The letter is to a friend invting him to your brother's marriage.
Body of letter:
You will be glad to learn that the marriage of my brother will be held on the 15th of this month. The marriage party will leave for Portus (city name) at 10:00 a.m. on the same day.
I therefore invite you to join us on this happy day. You will be of great help to us if you reach a day before the marriage day. I hope you will accept my invitation and will come to join us.
With best wishes.
,Your true friend.