English Vocabulary: Forenoon

In my Gmail, Word for the Day, I got this new word:

forenoon (noun) The period of time between sunrise and noon.
Synonyms: morn, morning
Usage: The heat of the sun awoke him early in the forenoon.

More about forenoon.

I learned a new word today. :)

Word Choice

"Thank you for letting us know of this matter.

We acknowledge your request to put your Smart Bro account on temporary hold due to recent typhoon and we would like to be of help.

We are sudden to hear about what happened to your area and we apologize for the inconvenience it may have caused you."

What is wrong with this letter?