Creating a mailbox on Exchange Server 2016 and Exchange Online:

 

Prerequisites:

• Exchange Server 2016 installed
• Active Directory (AD) associated with the server

 

There are two ways a mailbox can be created for a user and we’ll discuss both, by using the Exchange Admin Center (EAC) and using the Exchange Management Shell. I already have installed the Exchange Server 2013 on my Windows 2019 server.

Creating a UserMailbox through Exchange Management Shell

Open EMS on-premises server and the command we would use to create a mailbox would be as follows:

New-Mailbox -UserPrincipalName jchris@domain.com -Alias jchris -Database "Mailbox Database 1375581980" -Name JasonChris -OrganizationalUnit "beyounick.local/Synced OU/Users" -Password (ConvertTo-Securestring "Password@123" -AsPlainText -Force) -FirstName Jason -LastName Chris -DisplayName "Jason Chris"

The above command would create a mailbox with the UPN jchris@domain.com on the Database Mailbox Database 1375581980 in the OU beyounick.local/Synced OU/Users with password Password@123. It can be modified as per the needs. Let’s now check if we can see it on the GUI:

Through EAC

To access the EAC, we would go to http://localhost/ecp on a browser (http is used here explicitly as if it would try to fetch through https, it would give us certificate error):

Log in with the Admin credentials. It lands us to Recipients > Mailbox page by default:

Clicking on the + sign would give us 3 options as below:

The three options we see are User mailbox, Linked mailbox and O365 Mialbox:

User mailbox: A mailbox that is associated with people and this user mailbox has an associated AD account that gives the person the access to the mailbox to send and receive mail messages, and create meeting and appointments.

Linked Mailbox: A linked mailbox is a local mailbox that's associated with a user account in a different (trusted) Active Directory Forest.

Office 365 mailbox: You would only see this option if Exchange is set up as hybrid. This option creates a new remote mailbox on Exchange Online database.

 

We would be creating a User Mailbox for now, once selecting it, we would see the below screen:

We would be selecting New User to create a fresh new user mailbox with a new user in AD. This will automatically create the user in AD without manually creating a user and then enabling a mailbox for the same.

Fill in the details to create the user. The asterisk marked fields are mandatory to fill. If you have more than one domain added, you would have a dropdown to choose, select as needed:

We would save the changes made and once done, we can see a mailbox created on the Exchange Server database:

Notice that the primary email address domain it took was the local one. This is due to the email address policy I have in place. I disabled it and changed the primary email address to the one with custom domain. Can be done through Attribute Editor or by simply selecting the mailbox again and under email address, change to the desired one:

To disable the email address policy, open Exchange Management Shell and run the command as follow:

Set-Mailbox -Identity <Mailbox> -EmailAddressPolicyEnabled $False

Before moving further let’s see if the new user can send/receive emails. Log in to the newly created mailbox and I would be sending an email from an existing mailbox on premise to see if the new mailbox can receive emails. Log in to the new mailbox with the internal OWA link: 

 

It might ask you to select the home time zone on the first logon 

 

We were able to send the email from Test mailbox. Now let’s see if we received on the other side 

 

And vice-versa would also be successful. 😊