on 26-08-2022 11:14
I have recently swapped to O2 from Virgin, when I try to send text messages they come saying not delivered can you advise?
on 26-08-2022 11:21
I'll guess that you are using an iPhone?
If so, it's a known issue with iOS15.
O2's message delivery system is different to ther networks and not compatible with the changes made in iOS15.
To get an accurate delivery report, you need to start all your sms messages with *0# and just ignore the automated phone ones.