Login to your Gmail account and click on the gear icon at the right end of the screen and click on settings in the drop-down menu.
There will be a row of menu titles near the top of the next page. Click on Filters and Blocked Addresses.
At the bottom of the Filters section, click on Create a new filter.
In the small window that appears, enter firstname.lastname@example.org in the "From" section and click Create filter with this search.
Check the box "Never send it to Spam" and click Create filter.
If you want to ensure your subscribers do not need to take the above steps, create SPF and DKIM records.
If you have any questions, please don't hesitate to let us know. You can find all of our great support resources and how to get in touch with us via email, chat or phone on our Support Page.