Office 365 users have the ability to create different types of mailboxes, to increase collaboration and streamline communication within, and from, teams. But what are the differences between distribution lists, group email, and shared email?

Distribution lists

A distribution list can be used to allow a number of different recipients to receive the same information at the same time. Administrators can send emails to a large number of people at once, without having to type individual email addresses, or run the risk of accidentally omitting recipients. The ability to receive emails to the distribution list can be turned on or off.

With distribution lists, each member of the team gets their own copy of the email, so if one user deletes an email, it will only affect that single user. For example, a company might set up a distribution list that sends emails to all managers in a company, to let them know of company updates and information that will be of use to them.

Microsoft 365 groups

Microsoft 365 groups allow people to collaborate, as well as share resources such as documents in a shared workspace. A group can include a group calendar, and can be used by people inside and outside of your organisation. The administrator can allow external senders to email the group address, and also enable dynamic membership in Azure – meaning that members can be added or removed automatically, according to whether or not they meet certain criteria.

Microsoft 365 groups are essentially distribution groups in the way they route mail, but offer far more functionality in terms of the shared inbox, document library, shared calendar and more.

Shared email

A shared mailbox allows for multiple people to manage emails from the same email address.
For example, you may want all support emails to go to customerservice@yourcompany.co.uk, which you can then set up so that every member of your customer service team can have access. Replies can be on behalf of the shared email address, or from the user’s individual email. This means that support queries can be dealt with by any one of a number of people, and – importantly – everyone with access to the shared mailbox can see if an email has already been dealt with.

An important distinction from Microsoft groups is the inability to add users from outside of the organisation. There is also a maximum recommended limit of no more than 25 users per shared mailbox.

A (perhaps surprising) benefit of using a shared mailbox instead of a group is the impact on your carbon footprint. Every email takes up space in at least 2 data centres, and just one email with an attachment can cause up to 50 grams of greenhouse gas emissions. Only one copy of an email is required for a shared mailbox, whereas in groups, that email is copied over to every member of the group. This small difference in the way your teams manage their emails can add up to be a part of a bigger difference to your business’s overall carbon footprint.