To complete this scenario, you'll also need to configure your email server to send email messages directly to Office 365. This recipient could be a mailbox for your organization in Office 365, or it could be a recipient on the Internet. When this connector is set up, Office 365 will accept messages from your organization's email server and send the messages to recipients on your behalf. A connector from your own email server to Office 365.To complete the scenario, you might need to configure your email server to accept messages delivered by Office 365. To prepare for this mail delivery scenario, you must set up an alternative server (called a 'smart host') so that Office 365 can send email to your organization's email server (also called 'on-premises server'). When you set up Office 365 to accept all email on behalf of your organization, you will point your domain's MX (mail exchange) record to Office 365. A connector from Office 365 to your own email server.You need two connectors to route email between Office 365 and your email servers, as follows: How do connectors route mail between Office 365 and my own email server? Without connectors, email will not flow between Office 365 and your organization's email servers. If you have your own email servers and Office 365, you must set up connectors. When email is sent between Bob and Sun, no connector is needed.(All Internet email is delivered via Office 365.) When email is sent between John and Sun, connectors are needed.When email is sent between John and Bob, connectors are needed.

John and Bob both exchange mail with Sun, a customer with an Internet mail account: John has a mailbox on an email server that you manage, and Bob has a mailbox in Office 365. In this example, John and Bob are both employees at your company. The diagram below shows how connectors in Office 365 (including Exchange Online or EOP) work with your own email servers. You can enable mail flow between Office 365 and any SMTP-based email server, such as Exchange or a third-party email server. If you have EOP and your own email servers, or if some of your mailboxes are in Office 365 and some are on your email servers, set up connectors to enable mail flow in both directions. How do Office 365 connectors work with my on-premises email servers? Note: Before you get started, make sure you check on your specific scenario in What if I have my own email servers?.

You have (or intend to have) mailboxes in two places some mailboxes in Office 365, and some of your mailboxes are on your organization email servers (also called on-premises servers).

You have your own email servers (also called on-premises servers), and you subscribe to Exchange Online Protection (EOP) for email protection services.

This topic helps you set up the connectors you need for the following two scenarios:

Office 365 webmail