When you click, http://ibox.tim.it/mms you’ll prompted with the message saying:
Welcome in the space where you can read your MMS!
if you are a registered user, enter username and password in the spaces above.
If you are not registered, but you were sent an MMS TIM on your mobile,
Enter your phone number and the code that you received in the spaces below,
and then click “go”.
Quoted from Wikipedia:
TIM (Telecom Italia Mobile) is Telecom Italia‘s mobile phone brand, and runs a GSM, EDGE, UMTS and HSDPA network in Italy and Brazil. In Europe, TIM is part of the FreeMove alliance. TIM Peru was sold to América Móvil and rebranded Claro. TIM sold its share in the Venezuelan mobile operator Digitel TIM to Televenco, a company owned by the Cisneros Group, since then the company’s name has been Digitel. The agreement was approved by the Venezuelan regulatory authority Conatel. TIM Hellas, the Greek operator owned by Telecom Italia and previously known as STET Hellas (Telestet), was sold in 2005 to Apax Partners and Texas Pacific Group. In 2007 the company was sold to Orascom Telecom and TIM Hellas, Q-Telecom and also Tellas (a fixed phone/ADSL provider whose 50%+1 share is owned by Orascom’s Italian Wind) renamed to Wind on 5th of June 2007.
The operator was the third largest mobile operator in Europe by subscriber numbers at the end of 2007 .