Create an IMAP account
Open Gmail or any other webmail then, click on Settings
InSettings, select Forwarding and POP/IMAP tab
Now check the status of IMAP; if it is not enabled, then enable IMAP and Save changes.

Configure Outlook for Mac with an IMAP account
Open Outlook for Mac and then navigate to the Tool tab and select Accounts.
Now, choose Email and enter your email id, password, and other details.
Enter IMAP server and choose SSL connection along with SMTP server and 465 as a port number; then click Add Account.

Export Outlook for Mac emails to the IMAP account
Open Outlook for Mac then, Select the item you want to move.
Right-click on the selected folder, then Move> Copy to Folder.
Find the name of your IMAP folder and choose Copy.
After that, update the IMAP folder with Send/Receive button, and all your OLM emails are now in the IMAP account.

Configure Outlook for Windows With the same IMAP account
Open Control Panel and select Mail>Email Accounts> New
Select Manually configure server settings then, click Next.
Choose IMAP/POP settings then, click Next.
Enter your IMAP account credentials and Incoming and Outgoing server details, then clicks More Settings.
Click to the Advanced tab, enter the 993 port number in the IMAP server and choose SSL connection.
Enter the port number of the SMTP server as 465 and select SSL connection, then click OK.
Now, click on Next. It will take a few minutes, then click Finish.