Looking on the internet deeply has found these results:

I'm pleased to hear from you. is the most popular phrase on the web.

I'm glad to hear back from you. 123,500 results on the web	I'm pleased to hear from you. 176,400 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Yes, we've been waiting to hear back from you. She didn't show up for her last two classes, and I'm waiting to hear back from the hypnotherapist. I'm waiting to hear back from Dana on that. I'm waiting to hear back from a publisher. Let's wait to hear back from Ferg. And I'm waiting to hear back from garcia about tracking migrants Who may have traveled the same route as our unsub. Yes, we've been waiting to hear back from you. In any event, I... I've yet to hear back from you.	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

I'm glad to hear back from you.

123,500 results on the web

I'm pleased to hear from you.

176,400 results on the web

More popular!

Yes, we've been waiting to hear back from you.
She didn't show up for her last two classes, and I'm waiting to hear back from the hypnotherapist.
I'm waiting to hear back from Dana on that.
I'm waiting to hear back from a publisher.
Let's wait to hear back from Ferg.
And I'm waiting to hear back from garcia about tracking migrants Who may have traveled the same route as our unsub.
Yes, we've been waiting to hear back from you.
In any event, I... I've yet to hear back from you.

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.