The ‘MailboxNotEnabledForRESTAPI’ error relates to Microsoft and often occurs with the Outlook mailer. It typically occurs if the mailbox account you’re trying to authenticate doesn’t support REST API.
When setting up an SMTP plugin like Easy WP SMTP with the Outlook mailer, you’ll need to connect your mailbox account to the plugin via API connections.
If the email account you’re using doesn’t have REST API privilege, it will lead to the ‘MailboxNotEnabledForRESTAPI’ error.
Resolving the Error – Solution
To resolve this error, you’ll need to migrate your Microsoft Exchange mailbox account using the appropriate method. For steps on how to migrate your mailbox account, please see Microsoft’s official documentation.
Note: If the email account you’re using doesn’t have admin privilege, you’ll need to reach out to your organization’s Global admin to migrate your account.
Another solution to this error is to make sure that you’re using a valid Microsoft 365 mailbox. Using a dedicated mail account could lead to the ‘MailboxNotEnabledForRESTAPI’ error. Preventing your website from sending emails through the Outlook mailer