If you like to have Outlook checking for new messages as often as possible, because it allows me to take action on new messages as quickly as possible. I do not notice a discernible slowdown of my computer as a result of more frequent checks, so I find it to be a helpful adjustment. But if your situation is different and you want to increase or decrease the default 5 minute check frequency, you can follow the directions below to do so.
Step 1: Launch Outlook.
Step 2: Click the Send/Receive tab at the top of the window.
Step 3: Click the Send/Receive Groups drop-down menu in the Send & Receive section of the ribbon, then click the Define Send/Receive Groups option.
Step 4: Click the group for which you want to make changes (if you have not defined groups, then you can just use the default All Accounts selection).
Step 5: Change the value in the field to the right of Schedule an automatic send/receive every to the number of minutes that you want between each check. Note that I have set it to check every 1 minute.
Step 6: Click the Close button to apply your changes.