notify_url not working in sandbox

[jayersgould]

I cannot get the notify_url to fire at all in the Sandbox environment.  IPN SImulator gives "IPN was sent and the handshake was verified." message.  URL is active/online/accessible and gives no errors when accessing directly.  The entire sandbox transaction processes perfectly except for the IPN not being being called via the notify_url parameter.  I am at my wit's end trying to figure this out.

[MTS_Justin]

Hello,

There was a temporary interruption to IPN delivery which has now been resolved.

Apologies for any inconvenience.

Thanks !