1. Select File > Open & Export > Import/Export.
2. Select Export to a file, and then select Next.
3. Select Outlook Data File (.pst), and select Next.
4. Select the mail folder you want to back up and select Next
5. Choose a location and name for your backup file, and then select Finish.
   

ADD OUTLOOK DATA FILE TO MIGRATION TOOL

1. Download the migration tool (check if its 32 or 64 bit that you need)
2. Launch the Wizard using the desktop shortcut or execute the file 'ZohoMigrationWizard.exe' from \Zoho\Zoho Exchange Migration\bin folder, under the installation path.
3. In the Zoho Exchange Migration Wizard window, Click Next to proceed.
4. Enter the Zoho Mail credentials for the account you are importing into.
5. In the 'Migration For' dropdown, 'Self' will be selected by default if you're not an admin. Otherwise, select Self.
6. In the Migration Options, select 'PST Migration' and click Next.
7. In the User PST Details screen, click on 'Browse' and select the folder where you've stored the PST files.
8. The list of PST files stored for this user get listed on the screen. The PST files with which a problem was encountered during scanning will be indicated in red.
9. If you want to leave out certain folders in the migration process, expand the folder list and deselect the respective checkboxes. Click Next.
10. In the Migration Data Options screen, select the data that you want to migrate to the Zoho account. By default, all the parameters are selected. 
11. You can also edit your preferences directly in the Edit Options menu.
12. Make sure you have selected the right preferences for your accounts. You can't edit or access the previous screens once you've started the migration.

RUN MIGRATION

1. Click 'Start Migration' to begin the migration process.
   
2. Make sure you're connected to the internet throughout the entire duration of the migration.
3. The status column provides the details for the account being migrated.
4. You can click on the email address under the 'Account Name' column to view the detailed progress for that user.
5. The migration speed depends on the network speed, size of data to be migrated and other such factors. You will be prompted after the migration process is completed. In case you encounter any connectivity issues, you may choose to check your internet connection, and click on 'Retry Failures'.
6. If your system crashes or some other such error occurs the migration will be paused. The next time you login, you will be prompted that the previous migration is not complete. You can resume your paused migration if you want to.
7. Compare ZOHO mail with Outlook to ensure that the mails have been migrated.