I would like to share with you a reliable software Mac OLM to Gmail Export Tool that helps you to export Outlook offline. The tool comes up with many features. The file size is not mater the conversion task gets completed in just a few simple steps without manipulating the original files. It provides a free demo version which allows the users to save 30 emails/folder free of cost.
Once youre logged in, click the Settings icon in the top-right corner.
Click Settings.
In the Settings page, click the Forwarding and POP/IMAP tab.
From the IMAP Access section, choose Enable IMAP, and then click Save Changes.
Step 2 Add IMAP-enabled Gmail account into Outlook for Mac. The steps to add an IMAP-enabled Gmail account in Outlook on macOS will differ depending on the version of Outlook for Mac you are using.
Steps to Add Gmail Account in Outlook 2019/2016 for Mac
Open your Outlook for Mac application, and click Outlook >Preferences >Accounts.
In the Accounts window, click the plus (+) sign in the lower-left corner, and then select New Account.
When prompted, enter your Gmail account e-mail address and password.
Sign in into Gmail
Now, click Allow.
In the dialog box that appears, select Open Microsoft Outlook.
Click Done to start using Gmail in Outlook for Mac.
Transfer OLM File Data to Gmail
In your Outlook for Mac account, select the folder containing items you want to export to the Gmail account.
Right-click the selected folder, select Move or Copy to folder button.
In the pop-up window that appears, choose Gmail label name from the list, and then click copy.
Click Send/Receive to transfer all OLM emails to Gmail account.