Shared Mailbox vs Email Alias Microsoft

Scaling a business often means wearing multiple hats. One minute you’re the CEO, the next you’re the entire sales department and the customer support team.

As you grow, you likely need generic email addresses like info@, sales@, or support@. The common question we get is: “Do I need to pay for a new user license for every single one of these?”

Usually, the answer is no. You have two primary options within Microsoft 365: an Email Alias or a Shared Mailbox. Making the right choice now prevents workflow headaches later.

Feature Email Alias Shared Mailbox
Primary Use One person needing an alternate name Teams or Departments
Cost (License) Free (Included with user) Free (Up to 50GB)
Inbox Location Lands in your main inbox Separate inbox folder
“Send As” Capability Difficult (Requires configuration) Native (Easy to toggle)
Multi-User Access No (Password sharing required) Yes (Secure delegation)

Sending Emails: The Critical Difference

This is the number one pain point where users get stuck. An Alias is primarily designed for receiving email. It is a mask for your primary account.

If you use an alias (e.g., info@ points to jane@), replying to that email is tricky. By default, Outlook will send the reply from jane@. While Microsoft has made updates to allow sending from aliases, it often requires specific configuration and doesn’t always work seamlessly across mobile devices.

A Shared Mailbox solves this instantly. When you reply to an email in a Shared Mailbox, the “From” address automatically defaults to the Shared Mailbox address (info@), ensuring your personal address stays private and your brand looks professional.

Team Access & Security

Do you plan on hiring staff or an assistant? This is the deciding factor.

  • Email Alias: Only you can check it. To let someone else check it, you would have to share your Microsoft 365 password, which is a major security risk.
  • Shared Mailbox: You can grant access to multiple users. They log in with their own credentials and the Shared Mailbox appears automatically in their Outlook. You can add or remove members without changing passwords.

Licensing and Storage Limits

Both options are budget-friendly, but they function differently regarding storage.

  • Email Alias Cost: Free. However, the emails count toward your personal storage limit. If your user license has a 50GB limit and you get heavy traffic on your alias, it eats into your personal space.
  • Shared Mailbox Cost: Free. It comes with its own dedicated 50GB of storage. It does not require a separate license unless the mailbox exceeds 50GB or you need an Online Archive.

Mobile & Usability

Aliases are superior for mobile simplicity. Because the emails land in your main inbox, they arrive on your phone immediately without any extra setup.

Shared Mailboxes require a few extra steps on mobile. You typically need to use the official Outlook Mobile App and “Add a Shared Mailbox” to view it. It is distinct from your main inbox, meaning you have to toggle over to check it.

When to Use Which (Scenarios)

Still unsure? Here are three common scenarios:

  • Scenario A: “I just changed my name.”
    Verdict: Alias. If you change from Jane Smith to Jane Doe, keep the old address as an alias so you don’t miss emails.
  • Scenario B: “We just hired a receptionist.”
    Verdict: Shared Mailbox. Use reception@ so both you and the new hire can see incoming inquiries, but they can’t see your private CEO emails.
  • Scenario C: “I need a throwaway address for newsletters.”
    Verdict: Alias. Create newsletters@ to filter spam easily, then delete the alias when you’re done.

How to Convert an Alias to a Shared Mailbox

Did you start with an alias and now realize you need a Shared Mailbox? This is a very common transition as businesses grow. Here is the process:

  1. Remove the Alias: Go to the Microsoft 365 Admin Center, select the user, and remove the info@ alias. (This frees up the address).
  2. Create the Shared Mailbox: Go to Teams & groups > Shared mailboxes and create a new mailbox using that same info@ address.
  3. Add Members: Click on the new mailbox and select “Manage members” to give yourself (and others) access.

Note: It may take up to 60 minutes for the change to propagate through the system.

Shared Mailbox vs. Distribution Lists

Sometimes you don’t need an inbox at all. If you just want an email sent to team@ to instantly forward a copy to everyone’s personal inbox, you want a Distribution List (or Microsoft 365 Group). Unlike a Shared Mailbox, a Distribution List doesn’t store email history; it just blasts it out to the list.

Frequently Asked Questions

Can external users access a Shared Mailbox?

No. Shared Mailboxes are for internal users within your tenant. External users would need a Guest account, or you should use a Microsoft 365 Group.

How many aliases can I have?

Microsoft 365 allows up to 400 aliases per user, though managing that many would be chaotic.

Do I need a license to access a Shared Mailbox?

Yes, the person accessing the mailbox needs a customized Exchange Online license (Standard, Business Basic, etc.), but the Shared Mailbox itself does not require a license unless the mailbox size exceeds 50GB.


We Handle The Tech So You Don’t Have To

If the idea of configuring DNS records, navigating the Microsoft 365 admin center, or setting up permissions sounds like a headache, you aren’t alone.

Technical setup is a standard part of our Website Maintenance packages. We believe you should focus on replying to your leads, not wrestling with email servers.

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Technical Resources & Further Reading: