Hi Khalid,
About how to find the server name, you can refer to the following steps:
1. Sign in to your account using Outlook Web App (OWA).
2. On the Outlook Web App toolbar, click Help>About.
2. On the About page, under the External POP Settings line, use the Server name value to help you determine your server name:
(1). If the External POP Settings > Server name value includes your organization’s name, for example, pop.contoso.com, then your server name is the same as your Outlook Web App server name, without the /owa. For example, if the address you use to access Outlook Web App is https://mail.contoso.com/owa, your Exchange ActiveSync server name is mail.contoso.com.
(2). If the External POP Settings > Server name value is in the format podxxxxx.outlook.com, your Exchange ActiveSync server name is m.outlook.com. In some cases, Android mobile devices may experience connection problems using m.outlook.com as the server name. If you are having problems connecting, go to the Host name line on the About page. Use the value shown under Host name for the Exchange ActiveSync server name for your device.
Reference
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Set Up Exchange E-Mail on an Android Mobile Phone: http://help.outlook.com/en-US/140/dd940179.aspx
Thanks,
Anna Shi