Therefore, large messages (and any attachments) are downloaded only if you select them in the message list. Only message headers are automatically downloaded to your computer. If you have a slow network connection, you can use this option to improve performance. Secure Sockets Layer (SSL) is an encryption technology that helps improve the security of the account. To be able to edit the port number that follows the server address, select this check box. To find out the name of your Exchange server, you have to contact the person who gave you the email address, or contact someone in your IT department, for the name of your Exchange server. If Outlook cannot automatically detect your Exchange server, you can enter its address here. If you are using Outlook on a Mac, to access these settings from the primary Exchange Accounts preferences dialog box, in Outlook click File > the Advanced button, and then click the Server tab.

If you are trying to set up an Office 365 for business account with Outlook, see POP and IMAP settings for Outlook Office 365 for business for the incoming (IMAP) and outgoing mail (SMTP) server names. It's standard for them to provide you with this information so you can add your email address to a computer or phone. If you are trying to set up an Exchange account in Outlook, ask the organization that gave you the email address for the name of your Exchange server.

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