We are frequently asked to set up distribution groups (a single email address that create copies of each incoming message in inboxes for multiple people), or shared inboxes (a single mailbox shared by multiple people). In most situations, we recommend using a shared mailbox that everybody checks (as opposed to "spamming" a copy to multiple people).


The more people that are on a list, the more time that can be wasted in coordinating exactly WHO is going to reply or otherwise deal with a message.  Also, it's easy for each person to assume that "somebody else" is dealing with it.


Here are some pros and cons of each:


Shared Mailboxes
Distribution Groups
One copy of each message, accessed by multiple people in a special mailbox separate from their primary inbox.Multiple copies of each message, one in each person's inbox
As each message is handled, the user can move a message to a different folder or delete it so nobody else has to deal with it. Recipients need to coordinate who responds to each one to make sure that exactly one person (not 0, not 2+) responds.
MS 365 - Each user that accesses the shared mailbox must have their own mailbox (in the company domain)Works with external email addresses
Messages can be sent from the shared mailbox, and replies will come back to the shared mailboxMessages all originate directly from a user, and replies go directly to that user, unless the recipient specifically uses "Reply All"
Out of Office / Auto Responders are possible and come from the shared mailbox itself
Out of Office / Auto Responders are not possible on the group itself - Auto Responses from the members of the group may be allowed or disallowed to be passed on to senders (but not individually per-member).
Google Workspace - Cannot be accessed from mobile
Accessed just like any other personal email 
MS 365 - Free
Google Workspace - Charges normal user license
MS 365 - Free
Google Workspace - Free


Example Use Cases:


Shared Mailboxes
Distribution Groups
Access to former employee mailboxes
List of outside board members that all need to receive meeting minutes/notices
Generic emails (e.g. info@, sales@, support@)
Group eFaxes / voicemails