I'm not sure we want to distract Drew from Sourcehut (and running an email service sounds deeply distracting), but I would love to know what FLOSS email hosting

I'm not sure we want to distract Drew from Sourcehut (and running an email service sounds deeply distracting), but I would love to know what FLOSS email hosting service Sourcehut might see fit to support, as in the other thread about Openstreetmap.