Hello! My name is*****
Since you say you can receive e-mails just fine, then you are not really in the "Work Offline" mode, even though its button might tell you otherwise. I am not sure what the cause of the problem is, but if the problem is still there, here are several suggestions:
Repair the Microsoft Office (Outlook) installation
To do that, first exit Outlook and any other Office product. Go the Control Panel in Windows and click on Uninstall a program (Program and Features). When you see a list of all installed programs, locate Microsoft Office, right-click it and select Change. When a new window opens, click on Repair and continue. It will take some time until the installation has been repaired. When done, restart the computer. After the restart, check the results.
Load a new Outlook profile
In case the repair didn't work, the cause of the problem could be in a corrupted Outlook profile. For that reason, you can load a new one. To do that, press the Windows logo key and R key at the same time to show the Run... box. There type:
(there is a space between "k" and "/")
and press Enter
You should see the "Choose Profile" window. Click the New... button and give your new profile a name (any name), and click OK. You will then be asked to set up your e-mail account again, so do that. When done, click OK to start Outlook using the newly created profile.
Wait some time until your e-mails have been downloaded. Check how Outlook is working. If everything is fine, you can continue to use that new profile. To make it default, run the outlook /profiles command again and click the Options >> button and check the Set as default profile check-box, and click OK.
Let me know if this helped.