Voicemail time stamp no longer functioning

I have recently setup the Asterisk Voicemail send as an email feature. This works very well!

The concern is the the voicemail is stored, it is no longer being time stamped in the voicemail system, but it is being time stamped via the email notification.

Asterisk Version 1.8.15 on CentOS 6.5.

Any help is greatly appreciated.

I have resolved this issue. In the configuration for the voicemail to email functions there was an:
envelope = no

Changed to:
envelope = yes