I use mxroute for $5 a month and get unlimited email accounts on my domain and can have anythingatall@chven.us go to my main inbox. It also comes with Nextcloud which provides calendar, contacts, file sync. It is an older version of Nextcloud though. Also, my $5 a month might have been some special at the time I got it. But I've used it for almost 10 years with no big problems.

No password vault, but you could probably set up something that syncs with Nextcloud.