red envelope

These two days I received 2 red envelopes, I am very happy. That the two are mutually. Not the company, nor the elder relatives, that who gives me?

These two days I received 2 red envelopes, I am very happy. That the two are mutually.

(I am not sure what you meant by "That the two are mutually.") Did you mean that they contained the same amount of money?  

1. These past two days I received 2 red envelopes and I am very happy. They contained the same amount of money.

2.  These past two days I received 2 red envelopes.  I am very happy because they contained the same amount of money.

3. These past two days I received 2 red envelopes and I am very happy because they contained the same amount of money.

Not the company, nor the elder relatives, that who gives me?

1.  It is not the company nor my older relatives who gave them to me.

2.  They are not from the company nor from my older relatives.  Who gave them to me?