Whitelist Atlantia in Gmail

In your Gmail, click the Gear icon in the upper right corner
Click on “See All Settings” in the window that pops out
Click on the “Filters and Blocked Addresses” tab of the Settings window, then click “Create a new filter”
Set the From field to “atlantia.sca.org”, then click “Create filter”.
Note, do not click Search or you will have to start over.
Select, at least, “Never send it to Spam”. You can also flag it as important, or Star it, to make them more visible. Then click “Create filter”

Additional filter ideas:

Thanks to our kingdom jargon being pretty unique, you can create a filter for keywords using the format shown here either in “Subject” or “Has the words”. This example uses a few common event names. This filter may be handy if someone outside of @atlantia.sca.org is emailing you about an event and their messages are going to spam.

In my test this did highlight one spammy news article relating to the “coronation” of King Charles, so some false positives may still occur using this method.

Note the format for multiple matches is to surround them all with braces {}, and each term with quotes “”

Gmail Search Syntax Reference: