We are taking action, having been in receipt of a letter from him.

收到他的信之后，我们正采取行动。

《柯林斯英汉双解大词典》

I was spurred into action by the letter.

那封信激励我行动起来。

《牛津词典》

Following the proper formatting is only the first part of writing a letter that gets action.

写出有求必应的信，遵照合适的格式，只是第一步。

youdao

You never even had a small doubt that once his word was given, and a course of action decided, he would honor the letter and the spirit of the agreement."

VOA: special.2009.09.13

Genentech has never received an action letter from the FDA for its marketing of Rituxan.

FORBES: When Doctors Go Off-Label

"We have responded to the pre-action letter and are rigorously defending our decisions, " Ofqual said in an earlier statement.

BBC: Thousands of pupils to resit English GCSEs

In its pre-action letter, the alliance said pupils who took GCSE English in June had been treated with "conspicuous unfairness".

BBC: Thousands of pupils to resit English GCSEs