Outlook Can't Send With 3 Or More Emails On Bcc

I'm trying to send emails using BCC, i'am able to send emails with just 1 entry on BCC. The problem starts when i enter 2 or more email address under BCC. It doesn't stay on the outbox, it stays on the sent items. All the recipients doest receive the mail. And i'm having <rx> Mail queued for delivery. on outlook log.I tried it with another computer with same setup, same email account, same email, same recipients and number of recipients. 1 BCC entry went through and was received ok and i was also able to send with 3 or more BCC entry and email was received properly.