Why is it considered bad manners to leave the Subject field blank?
A.If there is no subject, recipients cannot use the Reply All feature to respond to the e-mail.
B.If there is no subject, the e-mail cannot be sent to more than one recipient.
C.If there is no subject, the recipient has to open the e-mail to see what it is about.
D.If there is no subject, the e-mail sends more slowly than an e-mail with a subject.