When composing a new e-mail message in Webmail, the Max Message Size of the e-mail message cannot exceed 16 MB (which includes text, html, images and attachments).  Also, if there are any attachments on the e-mail message, these files cannot exceed 15 MB in total.  If your Max Message Size exceeds 16 MB, when you try sending the e-mail message, you will get a message saying "Unable to send message at this time.".

When receiving messages to your Colony One e-mail account via Webmail or a third-party e-mail client such as Outlook, the Max Message Size of the incoming e-mail message cannot exceed 16 MB.  However, should the message exceed this size, the sender would receive a bounce back notification saying "Message size exceeds fixed limit", "Message size exceeds maximum allowed size...", or another similar message, and you will not receive the e-mail.