You manage a hybrid deployment between Microsoft Exchange Online and on-premises Exchange Server 2019. The deployment contains a primary SMTP domain named contoso.com.
Users have email addresses that use a syntax of [email protected].
A user named Ben Smith receives a new client computer. You configure the computer to access Ben Smith's mailbox. Ben Smith reports that he cannot connect to his mailbox from the new computer.
You verify that other users can connect successfully to their mailbox and that new users can discover their mailboxes by using Autodiscover.
You need to ensure that Ben Smith can connect to his mailbox from the new computer.
What should you do?