Case in point is the documentation around Shared Mailboxes. The Exchange Online Limits service description around shared mailboxes is very precise:
Shared Mailboxes have a 10GB limit for all plans, except Office 365 Enterprise K1 and Office 365 Government K1, which do not support shared mailboxes. It also specifies the following caveats in regards to shared mailboxes:
A user must have an Exchange Online license in order to access a shared mailbox. Shared mailboxes don't require a separate license. However, if you want to enable In-Place Archive for a shared mailbox, you must assign an Exchange Online Plan 1 or Exchange Online Plan 2 license to the mailbox. If you want to enable In-Place Hold for a shared mailbox, you must assign an Exchange Online Plan 2 license to the mailbox. After a license is assigned to a shared mailbox, the mailbox size will increase to that of the licensed plan.The purpose of imposing these limits is to prevent a customer from abusing shared mailboxes, such as licensing one mailbox and then giving a "free" shared mailbox to everyone else in the company to save licensing costs. There are other limitations for shared mailboxes, such as the inability to access them using ActiveSync, that also makes them unsuitable as regular mailboxes.
In-Place Archive can only be used to archive mail for a single user or entity for which a license has been applied. Using an In-Place Archive as a means to store mail from multiple users or entities is prohibited. For example, IT administrators can’t create shared mailboxes and have users copy (through the Cc or Bcc field, or through a transport rule) a shared mailbox for the explicit purpose of archiving.
As my ExtraTeam colleague, Chris Lehr, documents in his article, "Exchange Online Shared Mailboxes - Licensing, quota and compliance," the reality is quite different. Here's a summary of his findings:
- Shared mailboxes have a 50GB limit, not 10GB as per the documentation.
- You can put shared mailboxes on Litigation Hold or In-Place hold without licensing them, contrary to the documentation.
- If you put a shared mailbox on In-Place Hold, the Admin Console shows it's configured, but the Management Shell says it's not. In-Place hold does work, however.
All of this illustrates the need for clear, concise, and above all accurate documentation.
Unfortunately, Microsoft decided to lay off the Exchange technical writers in the latest round of cuts last month. Read Tony Redmond's article, "Microsoft layoffs impact Exchange technical writers - where now for documentation?" for his take on this. The presumption is that all Exchange documentation can be done cheaper in China, where most Office 365 development is done. While you're at it, check out "The best Exchange documentation update ever?"
This is another sad loss for the Exchange community but an even bigger loss for customers. How can they make good business decisions based on bad documentation?
My recommendation for shared mailboxes is to follow the official documentation for planning. You never know when Office 365 may actually enforce those limits or features.