Blind Transfer Behaviors:

• Menu Options of Call Menu - The transferred party will get forwarded to the menu option as if they selected that option from the call menu.
• Virtual Phone Numbers - The transferred party reaches the virtual phone number as if they dialed the virtual number directly.
• Forwarding Phone Numbers - The transferred party reaches the forwarding number as if they dialed the forwarding number directly.  If the forwarding number does not answer the call, the call will go to the forwarding number's voice mailbox and not a Talkroute voice mailbox. 
• Extensions - The transferred party reaches the extension as if they dialed the extension directly.  If the forwarding number does not answer the call, the call will go to the designated Talkroute voice mailbox. 
• Desktop Devices - The transferred party will get forwarded to the Desktop User 
• Voicemail Boxes - The transferred party will be sent to the voicemail box and hear the voicemail greeting associated with the box.

For more information please see this guide here: How to Transfer Live Calls.