Annapolis
Find the Annapolis Free Little Art Gallery at 801 Chase Street, North Entrance of Maryland Hall.
https://www.instagram.com/annapolisfreelittleartgallery
Greenbelt
Gallery Nineteen is Greenbelt, Maryland’s FLAG.
https://www.instagram.com/flagallerynineteen
Columbia
Free Little Art Gallery Columbia
https://www.instagram.com/flag_columbia_md

Potomac
FLAG Potomac
Can be found on 11819 Smoketree Road, Potomac MD 20854 and on Instagram https://www.instagram.com/flag_potomac
And yes, they accept art by mail, address it to Francesca Furchtgott.