bcc recipients disappeared

Hello, after I have sent an e-mail w/ a large number of bcc recipients, it's frustrating to not be ablet to go back and grab the e-mail and "reply all" to contact the same recipients. I usually can see the bcc recipients however, as son as I forward that same e-mail to someone else, my bcc list goes away on the original "sent" item and I no longer have my bcc list to even see who was on the e-mail let alone "reply all".