...
Click on the Mail icon.
Click on the Settings icon at the top bar.
Click on Automatic replies.
Click on Send automatic replies and fill in the details.
Once you're done, click on OK (at the top on the section).
...
...
Click on the Mail icon.
Click on the Settings icon at the top bar.
Click on Automatic replies.
Click on Send automatic replies and fill in the details.
Once you're done, click on OK (at the top on the section).
...