I got two texts from my network provider Orange yesterday - one which said: "We've updated settings to bring you the latest services. Please delete this message and then switch your phone off and on again."

How come I have to delete the text first and does anybody have any idea what 'new services' are supposed to be added to my iphone?

The second text was from a mobile number but said: "Hi from Orange. Your phone is now ready to use abroad."

How come the first message was tagged as being from Orange, but the second was from a mobile?

And with it saying your phone is now ready to use abroad, I thought you had to request that feature rather than it being set up automatically, and why now?

Was the second text from +447973100620?

If so, it's legit. Every so often, they'll pro-actively offer roaming to customers. If you don't want it, ring 150 and they'll turn it off again.

It's from 100610 so guess that's still official?

Do you have any idea why I have to delete one of the texts, turn my phone off and then back on again? Just sounds a bit strange.

Its a SIM update, your SIM isn't actually updated until you next turn the handset off and on. (Probably updating the roaming tables )

Think of it like a bit like a software update to a PC.

When your network services are updated, a change will be made on the network itself, as well as flashing your SIM to reflect it - possibly new menus or list of preferred networks etc.

The network end is pretty much instantaneous (with certain caveats), but your phone still needs to connect to the network with the new settings, otherwise the last "synchronisation" is using the pre-update settings. Hence power-cycling the phone.

This isn't a technically-precise description, but hopefully explains it. And as someone else has pointed out, outbound texts from Orange will generally come from 07973 100610 or 100620, in the same way as outbound calls from Orange CS use 07973 100194 as presentation-CLI.