I just bought it a few days ago and updated directly to this build.
For some reason I can't seem to get my office365 account added in the accounts menu. While adding it on port 993 with SSL/TLS and server outlook.office365.com it just can't make a connection to the server. Switching to port 443 always crashes the mail app
as a workaround I installed the outlook app, but that's horrible.
secondly: coming from a samsung device I had the option to define peak schedules to push mails and outside the peak schedule to sync manually. In the Blackview settings this functionality is apparently not available, causing my mails to come in at night, waking up about everyone in the building :p