We’ve been asked a few times if it was possible to create and share Exchange Online resource mailboxes (mail accounts that do not have a specific user but need to be accessed by more than 1 person).
The answer with BPOS is yes!
There is a bit of PowerShell required, so fire up that console and hit this link:
Given that administrators can’t modify Exchange delivery settings directly when using Exchange Online, something useful to know:
BPOS users can’t send to more than 5,000 distinct e-mail addresses in a single message. This does NOT mean you cannot send the message more than 5,000 distinct recipients (i.e. You can send to ONE Distribution List that has 23,000 members just fine).