In order to use Exchange Online / Microsoft 365 in connection with the various REDDOXX features, some prerequisites have to be covered.
Please follow the corresponding sections, depending on your use case.
Below you find the required documentation links for each of the REDDOXX features:
Mailsealer: LDAP / Mailflow
Spamfinder: LDAP / Mailflow
MailDepot: LDAP / Archiving with Microsoft 365