[SSSD-users] migrating from NIS to AD+kerberos

As a continuation of sssd evaluatin we plan migration from NIS to Active Directory+Kerberos. Now again the question - what is the best approach and practice to migrate users ? AD administrators enabled SFU, and we got extended schema with POSIX attributes. I guess there might be some free or commercial tools for extracting data from NIS and loading into AD -ldap objects. Our Linux users are dispersed in separated NIS domains, and all have AD account beside the entry in NIS. Home directories are NFS-mounted with autofs from Linux storage server but some users access MSWin storage with smbclient. Can you share experiences on assigning POSTFIX attributes in SSSD context, best practice etc..? We would not like activate NIS services on AD server for migration. Longina