Many email systems add an Apparently-To header to messages that only have BCC recipients. This header, if added, will list all of your recipients to your message anyway. To avoid this, you should add at least one To: or CC: recipient.
Mae sawl system e-bost yn ychwanegu pennawd Apparently-To at negeseuon sydd â dim ond derbynwyr BCC. Os ychwanegir y pennawd hwn, fe fydd yr holl dderbynwyr yn cael eu rhestru o fewn y neges beth bynnag. I osgoi hyn, dylech ychwanegu o leiaf un derbyniwr At: neu CC:.