it appears that Smart Telecom has switched their gateway on us. There is an update already posted to the App Store, we are just waiting for Apple to approve it.
Here is a temporary work around in the mean time!
In your settings, make sure “use iphone/ipod email” is ON.
When the email window comes up, change the address from: mysmart.mymobile.ph to: mysmart.com.ph and voila! it works!
thanks to Sue for pointing this out and providing the fix!!!!!!