3:30 PM PT -- MTV says the email we obtained doesn't tell the full story, which is that 'TRL' will be moving time slots, but it's also expanding.

A spokesperson says the show will be back in new "daily late night and morning shows this summer." The rep adds the show's been a huge success since its return.

MTV is pulling the plug on its revived version of "Total Request Live" ... TMZ has learned.

We obtained an email sent to employees informing them the series is being canceled once again. As you might know, TRL was brought back to the network in October, after being off the air for nearly 9 years.

According to the message ... TRL will not be returning April 9 as it was scheduled to after going on hiatus in February. Instead, the afternoon show will "pivot to short form content that will be featured on social and digital platforms."

Translation: MTV thought they'd greenlit 'Godfather: Part II," but it was more like 'Part III.'

Employees were told 'Total Request' late after shows will continue, along with a "Jersey Shore" after show on April 19 ... but 'TRL' as you know it, is officially done.