How to access my O365 account through the web?

  • By simply using a Web browser (Internet Explorer, Google Chrome, Firefox, etc.), you can access your Office 365 (O365 hereafter) account through the web, and access your O365 mailbox with Outlook Web App (OWA, the Webmail for O365).

  • For security and functionality, you are strongly recommended to use the most up-to-date web browser that is compatible with your operating system.

    If you use other Web browsers that not listed above, you will access your O365 mailbox with Outlook Web App opening in the light version, which provides fewer features for you to access your O365 account and mailbox.

  • You can access your O365 account by directly go to the "Office 365 for CityU" Sign In page at You can also get to this Sign In page by selecting "" from the CityU Email Services home page at

  • At the "Account-ID" field in the Sign In screen, please enter your O365 account in the form of "YourEID-c", where YourEID is your CityU Electronic ID).
    (e.g. if your EID is "cctom2", you should enter "cctom2-c".)

    Sign In

    Or, enter your O365 account-ID in full format as “YourEID–" (e.g. “”.)

    Sign In

  • At the "Password:" field, enter your O365 Account password. Then click the [Sign in] button to login your O365 account.

  • After successfully login, you will get into your O365 account mailbox with Outlook Web App (OWA) - a powerful Webmail system. You can use it to read and send e-mail messages, organize contacts, create tasks, and manage your calendar.

    To know more about OWA, please visit "Getting Started with Outlook Web App" at

  • When you finish using your mailbox, always remember to Sign out your account with the following steps. Signing out helps prevent someone else from using the computer to access your mailbox.

    1. Click your account at the top-right corner of OWA window.
    2. Select Sign out.


  • After signing out, you will be directed to Microsoft's "Sign In to Office 365" page. To go back to CityU Office 365 Sign In page, you can enter your O365 User ID (e.g., note that it is "", NOT "") at the "account" field (the first field), then press Tab key or move your mouse pointer to the "Password" field, as shown below:

    Sign In to Office 365

    Without typing anything in the "Password" field, you will be automatically re-directed back to the CityU Office 365 Sign In page.


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