如何用英文表达"我将会出席"的意思?

问题描述:

如何用英文表达"我将会出席"的意思?
有一封来自某机构的电邮邀请我参加某活动, 在电邮中提及"Please confirm your attendance by replying this email"
请问我如何得体地回答他"我能够於当天出席"?

I'm pleased to confirm that I will be present at the event on that day/I will attend the event on that day.