Lets Straighten out On-Premise Rights Included with M365
A quick internet search is likely to find conflicting views on what on-premise rights you are granted with your M365 Subscription particularly in relation to server software. Many sites will state that you gain only user access rights with your USL licenses, ie. essentially a CAL license entitlement, and that you are still required to acquire the server licenses for the likes of Exchange and Sharepoint.
Simply, that's not correct.
Firstly though, be sure of the M365 Subscription you are dealing with as each will offer different content and scope. The CAL/ML equivalency table of the Product Terms provides a good overview to this:
Note for example that the common business E3 and E5 plans provide both Base and Additive access rights for Exchange and SharePoint Server. But what about the Server Licenses?
A quick browse through the FAQ of the M365 Site provides the first hint that certain Server software is indeed included:
While the respective sections covering the likes of Exchange or SharePoint Server software don't provide any clues, the Microsoft 365 section clearly articulates the entitlement (page 57 of the October 2019 document):
Assuming all of your users are properly licensed (and they should be) your on-premise Exchange, SharePoint and Skype for Business Server installations are covered!
... and that includes back-versions of course under the Universal License Terms part 3 - "Rights to Use Other Versions and Lower Editions".
So no need to True-Up those on-premise Server licenses for Exchange or SharePoint, and who isn't keen for less overhead and more funds right?!