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Illinois State University

Sending Mail in Office 365 Email Online

How to send and respond to messages using the Mail app in your Illinois State University's Office 365. The following refers to using the Outlook Web App.


Office 365 email 


Illinois State University's Office 365 Email can be accessed through the web, via an email client (such as Microsoft Outlook or Mozilla Thunderbird), as well on mobile devices. Office 365 email is the primary campus email and calendaring service for campus.


Sending Mail in Office 365

To send a new email in Office 365, do the following:

  1. Go to, log in with your full email address (ex;, and launch the Outlook app by clicking the Outlook Icon.

- For more information, refer to How to Launch Apps in Office 365

  1. Click New Message at the top left of corner of the screen, above your inbox.



  1. A new message will appear in the message pane on the right.
  2. Enter the email address of the person or organization you wish to email in the To box.
  3. Enter a subject for your message in the area labeled Add a subject.
  4. Type the content of your message in the space below.
  5. When you are finished, click Send.

When sending from your ISU email account, simply typing the last name, first name of a faculty or staff member will bring up that person's email address. Students are not included in this function.


Replying to an Email

To reply to an email, do the following:

  1. Go to, log in with your full email address (ex;, and launch the Outlook app.

- For more information, refer to: Checking Office 365 Email Online

  1. The Outlook Web App will open and display your Inbox
  2. Click a message in your Inbox to view its contents. Double click the message for a pop out of the message.
  3. Click the Reply all button to respond, or click the drop down arrow next to Reply all for other options.

- To change the default settings to be "Reply", go to Reply Settings in the Options menu.

  1. Add your response and click Send at the top of the message. 

Adding Recipients

To add recipients do one of the following:

  • As you type in the To field, Outlook Web App will display matches it finds. Click on one of the matches to add that email address to your message.
  • Clicking on To (or Cc or Bcc) will bring up your Office 365 My contacts list and allows you to add recipients.
  • Searching My contacts returns matches from both your personal contacts and the University's people directory.
  • Use the Cc field to send a copy of your email to one or more additional recipients.
  • You can add the Bcc field by clicking the three dots above the message. From the menu, click Show Bcc.
  • To remove a recipient before sending the message, click the x next to the item you want to remove.
  • Multiple email addresses must be separated by semi-colons.

Adding Attachments

You can attach files to your email by clicking Attach above the message. This allows you to attach files stored in OneDrive or on your computer.




- You can also attach files by dragging and dropping them into the body of the message.


- To remove an attachment before sending the message, click the x next to the item you want to remove.


- The size limit on sending email in Office 365 is 50MB. This size limit applies to the message contents itself, as well as any attached files.


How to Get Help


For technical assistance, please contact the Technology Support Center at 309-438-4357, or by email at


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