System Users or leftovers from AD/Exchange Takeover?

[toko42]

I’ve found some users in my system which are not listed as system users here:

UCS built-in system users

[Produktlogo UCS] UCS 4 There are several relevant system users in LDAP created automatically by UCS and not counted in license. The following users are essential and created in each UCS environment: username description Administrator Basic administrative account. Is member of the "Domain Admins" group join-backup System account used for joining DC Backups join-slave System account used for joining DC Slaves The following system users are created in…

SM_5c977e3075d840999 MSExchApproval
SM_6fa4a7d4e74d4fcfb MsExchDiscovery
SM_8cdc4c19f298483fb FederatedEmail.
SM_15dc6b554e5e4197b MsExchDiscoveryMailbox

The righthand names are followed by a string of letters and numbers.

Can I delete those users safely?
Or at least hide them as they are listed in nextcloud also which bloats the list.

Thank you very much!