Let’s say all your applications/devices meet those requirements. So let’s walk through a couple of scenarios. So it’s pretty clear that Microsoft does not want you sending mass mailings using Office 365. The account you authenticate to the relay server with must be the same account as the from the address on the messages you send through the relay.Īnd if those requirements aren’t strict enough, an account is limited to sending 1500 messages per day.The sending application must authenticate with Office 365.The sending application must support TLS.The sending application must connect to the Office 365 servers on port 587.Requirements for SMTP Relay with Office 365 If the answer to the question above is No, your application or device needs to send mail to both people on the Internet and in your domain, then you need to relay mail. Granted it will look a little strange to Forefront that mail is coming from the Internet with a source address of but by adding the IP address(es) of the on premise devices sending mail to the safe senders’ list, you should be able to avoid those messages going to junk or getting quarantined. When the mail comes into Office 365 in this scenario, it will be accepted like other messages from the Internet. No authentication is necessary, no special ports are necessary. You can configure those applications/devices to send mail directly to your MX record in Office 365. If the answer is Yes, then you don’t need a relay server. The question you must ask yourself to determine if you really need a relay is: Do my applications, scanners, etc need to send ONLY to people in my domain? It seems there is some confusion about what actually constitutes a relay, so let’s start off with trying to determine if you actually need to relay with Office 365 and then we’ll get into the options. This will display your incoming (IMAP) and outgoing (SMTP) mail server information to use as your Source Server information.SMTP Relay with Office 365 is one of the more common questions we get at MessageOps.Select the email account that is your old email account.Adding webmail accounts to email apps such as Outlook, Apple Mail, Thunderbird.POP works by contacting your email service and downloading all of your new messages from it. IMAP allows you to access your email wherever you are, from any device. You can also enable Auto-Expunge and configure Folder Settings.Under the IMAP section, check the IMAP Access box.Navigate to Mail Accounts and click the respective email address from the left listing.To enable IMAP Access for your email account: You must type your complete e-mail address. This is how your name appears in the From field of e-mail messages you send. You can label your Outlook account with any name you choose. The following table provides information and tips for entering basic IMAP settings in the Outlook Accounts preferences dialog box. Info about Imap Settings For Network Solutions What are my IMAP settings? IMAP account basic settings.