Hello,
At first let me give you some preamble.
We're going to offer to use Hybrid Exchange environment to one of our customers because of problems with current configuration. Currently they use a bit complex email routing scheme - one part of organization uses Plesk Panel mailboxes while another department uses Exchange 2013 server. Both sides shares 1 email domain name. Plesk Panel server holds an MX record and redirects messages sent to non-existed recipients to some special mailbox. There is a pop3 connector running on Exchange 2013 server which periodically fetches new emails from that special mailbox and re-sends them to Exchange users. As you see it's not the best configuration. The customer also interested in using Sharepoint Online for both Active Directory users and Office365 users. End of preamble :)
My questions is:
What is the most cost effective Office365 subscription should we use to build such environment? Main requirements are: co-existence of on-premises Exchange server and Exchange Online + Sharepoint Online for ALL users (on-premises Active Directory users and Office365 users).
Currently we're going to offer "Office 365 Enterprise E1" subscription but I'm still not sure whether it will be possible for all users (AD and Office365) to use Sharepoint Online.
Thanks in advance.
PS. Sorry if something is unclear. I can give more details.
Marat Nasirov
