Shared Mailbox for 50 field users who have iPhones

[Floyds_on_Greenwood]

Greetings. We have 50 or so field users with iPhones. These field users all use the same account to connect, via ActiveSync, to the 'field' mailbox. *The field mailbox is used for Contacts and Calendar on iPhones. Very seldom if ever to send or receive email.

With our legacy on-premise Exchange we could utilize a 'field' Active Directory account to connect to this user account associated mailbox via ActiveSync. We did have to increase the maximum concurrent connections beyond the default limit- quite a bit actually.

We are (forklifting our network) creating a fresh/new on-premise active directory domain (no on-premise Exchange) and using ADConnect to sync the AD User accounts to O365.

It looks like we will not be able to increase the maximum concurrent connections in our O365 tenant to facilitate the same 'field' mailbox connectivity across these 50 or so mobile devices (iPhones).

I am wondering if we can:

Create a 'Field' user account in our ADDS.

Create the O365 Mailbox for this ADDS Account. License the O365 account.

Convert the O365 'field' user mailbox to a Shared mailbox.

Connect to this 'field' shared mailbox using its associated ADDS/0365 account on all 50 of these iPhones using (preferably) ActiveSync without any concurrent limitations (full functionality without error).

Is this possible? Will this work as we desire? Are there any concurrent connection limitations with an O365 shared mailbox using ActiveSync? What about The Outlook app using ews (i believe?).

[#2]

no, a shared mailbox can only be accessed indirectly through because the Microsoft license agreement states that you must assign a separate license for every human. Once you license everyone, then you can use a shared mailbox using the Outlook Mobile App (not Activesync). https://support.microsoft.com/en-gb/office/add-a-shared-mailbox-to-outlook-mobile-f866242c-81b2-472e...