CiviMail does not send mailings to members of group who have 'do not email' setting selected (good). But it would better if the reporting screen for mailings would list either group members or the number of members who have this setting enabled and therefore were not sent the email.
As it exists now, if there are 5 members in the group and two have 'do not email' settings, the reports say that 3 members were sent emails and that 3 were delivered successfully. However, if you don't know the number of people in the group, this reporting isn't very helpful. Would be better to say 3/5 were sent emails, or to list the group members who have 'do not email' attached to them in a separate table, or to give a numerical listing below sent emails of number of group members not included in mailing with a link to view those group members.