The #1 reason emails are missed is because conversations are defaulted to on. Conversations in Outlook groups emails together with the original on the bottom and when people reply, you may miss the original. To turn off this pesky feature, simply do the following:

Outlook App:

1. Click the Icon located in your inbox:

2. This will bring up a menu for inbox options and choose “Settings”:

3. On the Settings tab, uncheck “Show email grouped by conversation”.

 Outlook Webmail:

1. Click on the gear icon located on the top right of your menu bar:

2. This will bring up your Settings tab. Under “Message Organization”, choose “Show email as individual messages”: