If you calmly look at the reply you sent to an email, you'll find that it'll have "you" all over it. While you may use the pretext that you're just working with whatever information the addressee gave you, in the end it's just all about yourself. This is wrong. Let's be a little more careful, shall we?

He delayed payment on some pretext or other.

Some arrangements about his horse and baggage formed the pretext for his sudden retreat.

He came to my house on the pretext of seeing me.

He used the fact that his sleeve was caught in the brambles as a pretext to do nothing.

... reason? What you're looking for is a pretext, isn't it?

Whereas before I had no pretext on which to give an account of my life, now I have got one.

The Japanese fishing fleet catches more than 1000 whales per year on the pretext of scientific research.

He made up a pretext for a fight with me.

He fired me and offered a pretextual rationale for the firing.