MXRoute plus Nextcloud is a viable groupware alternative, generally at a much lower cost per user.
One of the bonus features being your email is much less likely to disappear within Outlook.com's mailservers. Not sure what is going sideways there, but those mailservers are not reliable and mail traces are ineffective in finding lost emails that have proof of delivery to the MX record listed outlook.com mailserver.
One of the bonus features being your email is much less likely to disappear within Outlook.com's mailservers. Not sure what is going sideways there, but those mailservers are not reliable and mail traces are ineffective in finding lost emails that have proof of delivery to the MX record listed outlook.com mailserver.