Deciding which group email solution is right for your department or office is important, but it can also be confusing. 

Here, we've broken down the features available with each option. 
Which Option Is Right for You?

Collaborative Inbox (Google)  

Shared Mailbox (Google)   Mailing List (Sympa)                                               
Receive email to a shared email address (e.g., Yes Yes Yes

The group address name will end with
Respond to email sent from outside users Yes Yes Yes

The list moderator can enable this in the list settings.
Send new email (originated by the group email account) No

Group members can choose to send as the group when composing messages in their own individual inbox.
Yes Yes
Sort and archive email in labels (folders) No Yes No
Assign emails to other group members (like tasks) Yes No No
Filter email by tags Yes Yes No
Share a calendar with group members No Yes No
Manage group membership Yes

The group owner adds members to the inbox.

The group owner delegates access to the account for up to 25 people.

The list owner can manage subscribers and admin permissions.
Create a mailing list of users for sending regular emails No No Yes
Requires OIT setup Yes

Once the account is created, the group admin can update membership. 

Once the account is created, the group owner will be able to delegate access for up to 25 people.

Anyone can make a custom mailing list. Only approved users, however, have access to pre-defined Restricted Lists.