I’ve used OpenXchange and Zimbra, quite a few years ago. They were OK.
Afterlogic is nice, provided for regular accounts at MXroute. The mobile interface doesn’t provide calendar and contacts, but the webmail works well. If you use the desktop web interface for contacts, it works fine, but if you import a lot of contacts, chances are you will have to use another CardDAV client to clean up contacts (it’s picky as to which phone numbers and email addresses it shows).
Crossbox is nice and fancy, but for webmail I actually prefer RoundCube (which Crossbox also provides, along with other webmails, NextCloud, Mattermost and more). AFAIK native Crossbox doesn’t offer calendar and contacts.
Never tried Axigen. I personally hardly ever use webmail, so not sure if I will, either, as it did look fancy/expensive …