I just got it for email hosting at $3/mo, but they provide a host of other tools aimed towards businesses.
Second, even if you do need to change apps, you don't need to change addresses if you have your own domain.
Mailbox.org as of now seems to be good except that they have started to either reply to emails quite late or sometimes simply ignore it[0] and the general lack of non-German language pages across their portal [1].
[0] Maybe because they have officially stopped anything but community/forum support for paying customers in €1 and €2.5 per month plans -https://mailbox.org/en/fees-and-conditions/
[1] https://help.mailbox.org/servicedesk/customer/user/login?des... Yes, one can guess or use Google translate but there's no translated page for this.
You are aware they're an Australian company that will be forced to provide Oz government access to your account?
I wrote the comment especially in the light of people tripping across parent's recommendation. (There are lots of other threads here on HN indicating how people wish to migrate from gmail to something else, due to other Google/Alphabet Inc issues.)
"Where requests for access are issued legally, we comply." [0]
[0] https://fastmail.blog/2018/09/10/access-and-assistance-bill/
https://posteo.de/en https://posteo.de/en/site/transparency_report