I toggled the yes/no box "Allow mail from logged in contact" to yes, but it doesn't affect the "new mailing" screen which is really the most important one for me. Can I change this somehow? Is there another yes/no somewhere? If not can I put in a feature request for it?
I guess the "Allow mail from logged in contact" option is for sending Email Activity or Contribution receipt but not bulk emails. Might be because if the bulk emails are not send using site domain address than it end ups in users spam box.
Its a good idea to raise for a feature request on https://lab.civicrm.org/ or you can implement an extension to include logged in users id.