Anti-Spam Discussion Forums

[Skewed]

Hi,
I dont know if this is the correct place to post this, I apologize if its not. I have a question about From lines and sending email.

I work for a university that regularly sends out email to our alumni. We also use a third party to actually send the email, but we are having an issue with what happens on the From line. This is a new third party to us and our previous vendor did not have this issue.

Currently, every time we send an email, the from line reads:
From: 'noreply@ourthirdparty.com on behalf of myuniversity@university.edu'

They tell us it must be this way to comply with the spam laws, which I am ok with, but this from line does cause some issues with our alumni. As I said, our previous third party was able to address the From line as it should be:
From: myuniversity@university.edu'

Can someone shed some light on this for me please. Does any know why the emails "must" be sent on behalf? I somewhat understand, but also some of it also raises my BS flag. TIA