From a technical point of view, you can. But we strongly suggest not to use normal email clients (such as Mozilla Thunderbird, Microsoft Outlook or Apple Mail) when it comes to send mass email newsletters, putting all addresses in CC or BCC.

As a matter of fact, CC/CCN technology hasn't been designed for email marketing and can lead to delivery issues. So if you want to use turboSMTP on your client for basic, one-to-one email communications, there's no problem. But if you need to use our SMTP server for a bulk email sending, you should absolutely avoid CC/BCC and rely on a professional tool such as SendBlaster.