Best practice for user and contact management and mailing lists

Hi all,

I’m looking to use nextcloud for my organization with circa 500 members.
We’re divided into different groups.
I want to be able to E-Mail all group members by using a list like in Outlook (e.g. Department A -> all people in Department A get an E-Mail).
Also, I want everyone to be able to synchronize their group’s contact information on their phones or inside their own mail clients (Outlook etc.).

What’s the best approach with NextCloud for this? Should I use an LDAP and integrate NextCloud with the LDAP and use the LDAP as the main user directory?

The regular CARDDAV funcionality seems to be not so well integrated for Outlook and does not make groups selectable as recipients on iPhones. Am I missing something here?

Any hints are welcome. Unfortunately I did not find anything for this use case.

Many thanks