Add Dynamic Distribution List in O365 Security Group

Hi bhanu chintha

As this article shows

- You can have dynamic security groups

- You can have dynamic office 365 groups

https://docs.microsoft.com/en-gb/azure/active-directory/fundamentals/active-directory-groups-create-...

You set these in Azure AD. You cannot add a dynamic distribution list to an existing security group.

This should answer the question you originally had. 

These will help you create such a group based upon dynamic rules

https://docs.microsoft.com/en-gb/azure/active-directory/users-groups-roles/groups-create-rule

https://docs.microsoft.com/en-gb/azure/active-directory/users-groups-roles/groups-dynamic-membership

I do not think you would need to enable external sharing on SP site collection to give permissions directly to DDL - this is for users outside of the organisation.

Best, Chris