Outlook 2016 - IMAP Email Account Stopped Functioning

Sometimes the PST and OST files get corrupt, and Outlook stops working. This guide shows you how to reset Outlook 2016.

Before you start

Outlook stores data in .PST and .OST files with a maximum size of 50GB. Make sure your computer has enough disk space, at least 50GB.

Performance drops at 12GB or about 12,000 messages in a single folder. Keep your Inbox clean by creating folders and moving messages you do not need into them. Outlook runs best with an Inbox of 4GB or less and fewer than about 1,000 messages.

Part 1: Back up your calendar, contacts and tasks

If you have calendar appointments, contacts or tasks, back them up first. You will put them back at the end.

Step 1: Open File

Go to File.

Step 2: Open Import/Export

Click Import/Export.

Step 3: Export to a file

Select Export to a file and click Next.

Step 4: Click Next

Click Next.

Step 5: Pick what to export

Select Calendar (or Contacts or Tasks) and click Next.

Step 6: Click Browse

Click Browse.

Step 7: Name the file

Name the file Calendar (or Contacts or Tasks). It is saved in your Documents folder. Click OK.

Step 8: Click Next

Click Next.

Step 9: Click Finish

Click Finish.

Step 10: Set a date range

Set a date range and click OK.

Step 11: Repeat for the others

Repeat steps 1 to 10 for Contacts and Tasks.

Part 2: Remove your Outlook profile

Step 12: Close Outlook

Close Outlook.

Step 13: Open Mail in the Windows Control Panel

Open the Windows Control Panel. In the drop-down at the top right, select View by: Large icons. Then click Mail.

Step 14: Show profiles

Click Show Profiles...

Step 15: Remove the profile

Click Remove.

Step 16: Confirm

Click Yes.

Part 3: Create a new profile

Step 17: Add a profile

Click Add.

Step 18: Name the profile

Name the profile EnGuard and click OK.

Step 19: Enter your details

Fill in the following, then click Next.

A) Your name. Recipients see this on all outgoing messages.
B) Your email address
C) Your password, typed twice

Step 20: Choose to change settings

Check the box for Change account settings and click Next.

Step 21: Open More Settings

Click More Settings ...

Step 22: Set the outgoing port

Go to the Advanced tab.

Set Outgoing server (SMTP) to port 587.

In the Use the following type of encrypted connection drop-down, select STARTTLS.

Click OK.

Step 23: Finish

Click Finish.

Step 24: Close

Click Close.

Step 25: Click OK

Click OK.

Part 4: Put your calendar, contacts and tasks back

Step 26: Open File

Open Outlook and go to File.

Step 27: Open Import/Export

Click Import/Export.

Step 28: Choose Import

Select Import from another program or file and click Next.

Step 29: Click Next

Click Next.

Step 30: Find your saved file

Click Browse and select the Calendar file you saved earlier (or Contacts or Tasks). Click Next.

Step 31: Pick what to import

Select Calendar (or Contacts or Tasks) and click Next.

Step 32: Click Finish

Click Finish.

Step 33: Repeat for the others

Repeat steps 26 to 32 for Contacts and Tasks.