Gmail Setup
Step 4 - test transport
When transport successfully saved you can see message above transport grid.
Now you have to test new transport.
Click on a row with new transport in grid or click Edit in Action
column. This opens Edit Email Transport page. Click button ✔ Test Email Transport
.
If you get success message then transport works fine and you can check your inbox at gmail. You will find there email with subject “Test Email Transport …“. Now you can go to final step ▶.
But there is a big possibility you get an error message similar to message on screenshot below. It means that Magento cannot login to gmail account due to its security settings. Check next step to find out how to fix it.