At my real job, we use Office 365 with mixed licenses [E1s & E3s].
The E1 licenses only give you access to email; and although it’s a pretty cheap subscription – if you tally enough of them, you’re going to get hit hard on a monthly basis.
In Outlook 2016, which has been out for some time now, they added a feature called Outlook Groups. With this, you can create a separate email for, say, support or information – like Info@SorryAboutYourCats.com or something along those lines. Then, with your other account, you subscribe to the group – which gives you access to the shared mailbox along with some pretty neat collaborative features.
Of course, this means you’ll need at least one Office 365 account – but it’s better than owning, say, 7 different E1 accounts that have to do with different subjects.
There are other ways to achieve this too, by having different email accounts forward to one without any additional cost – but with Outlook Groups, the emails are organized without the use of filters and rules.
Well – you get the picture! Check it out if you’re interested!