An email alias is an additional address that delivers to an existing mailbox. For example, an address for enquiries could arrive in a mailbox you already use, rather than requiring a separate login.
An alias is not another inbox
Messages sent to the alias are handled by the destination mailbox. It does not normally have its own password or independent storage. If several people need to manage a team address, a shared mailbox may be a more appropriate arrangement.
Check sending as well as receiving
Being able to receive at an alias does not automatically mean every mail app can send from it. Sending permissions, reply behaviour and the number of aliases depend on the provider and account configuration. Do not assume aliases are unlimited.
Common uses
An alias can keep an older address receiving mail, provide a role-based address or avoid publishing someone’s personal address. When a person leaves a business, access and ownership need a proper review; forwarding everything to another employee is not an automatic substitute for that process.
For help choosing an arrangement, explore our Exchange email and Microsoft 365 administration services.