I installed swirly mms on my O2 contract iPhone 3G 2.1 firmware with the below settings but it seems to be sending messages but when I use my wife's 1st gen iPhone to send a message to my 3G iPhone I only get a text telling me that I have received a media message but swirly will not receive it in the inbox.
I'm pretty sure O2 have to enable mms on your account and because they know the iphone doesn't do mms they won't. At least thats what I was told on the three occaisions I tried to get it sorted.
I had swirly mms working and receiving messages before I upgraded from the 1st gen iPhone to 3G so I dont know why it wont work now, also it should not make any difference to O2 if I jailbroke my iPhone because it would only void warranty and I didnt purchase insurance when I bought the phone anyway.
Anyway I sent an email to O2 about it because there's a problems with the website sending mms settings so I'm waiting to hear back from them.