Multiple emails in bcc list throws error

I am using System.Net. Mail to send emails. It works fine if I add multiple emails in cc but as soon as I add them in bcc I get an error message "Insufficient system storage. The server response was: 4.2.2 Mailbox full"
Here is the code:
foreach(var address in bccclist.BccRecipient.Split(new[] {";"}. StringSplitOptions.RemoveEmptyEntries))
{
email.Bcc.Add(new MailAddress(address));
}
//code for sending email
bccclist.BccRecipient contains string of multiple emails a@gmail.com;b@gmail.com;c@gmail.com;d@gmail.com