We are facing an issue where in if we add 350 email id's in Bcc list not all users receive the email. So we have been asked either to add all email address in a single line or add Bcc: field against every email address. Any idea if that will help resolve the issue. We are currently adding multiple Bcc email id's in the header using message.AddHeaderField2("ckx-bcc", "firstname.lastname@example.org"); method. But when we check the eml file only 1st email id is present in eml file. So can we know why this is failing. Also if there is any way in which we can add all email id's in a single line.