Exam MS-100 topic 2 question 49 discussion

Your company has two offices. The offices are located in Seattle and New York.
The company uses a third-party email system.
You implement Microsoft 365.
You move all the users in the Seattle office to Exchange Online. You configure Microsoft 365 to successfully receive all the email messages sent to the Seattle office users.
All the users in the New York office continue to use the third-party email system.
The users use the email domains shown in the following table.

You need to ensure that all the email messages sent to the New York office users are delivered successfully. The solution must ensure that all the email messages for the users in both offices are routed through Microsoft 365.
You create the required DNS records and Send connectors.
What should you do next from Microsoft 365?