iPhone MMS Update: Roll-out has begun by Philip Elmer-DeWitt @FortuneMagazine September 25, 2009, 4:42 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Photo: Apple Inc. Friday was D-day for AT&T T . Having promised to finally give its customers MMS — the multi-media messaging capability Apple AAPL included in its iPhone operating system two releases ago — the carrier faced two major challenges: It had to deliver the service on the time and date promised: late morning Pacific Time on Sept. 25, according to a message posted on AT&T’s Facebook page earlier this week The service had to work as promised without slowing the network to a crawl — or, worse still, bringing it to a halt. Although it seems to have achieved the former — Apple issued a support article with update instructions shortly after 10 a.m. PT — the latter may be harder than it sounds. iPhone owners have not been shy about voicing their complaints about AT&T’s sluggish and spotty service, especially in recent months. Having seen the surge in traffic created by advance MMS testing among selected groups of customers, the carrier was said to be “highly anxious” about what would happen when the service was turned on nationwide. MMS allows users to send graphics, audio clips, locations, contacts, and video clips via an SMS-like messaging system. It’s been available since July to iPhone users in other countries, but AT&T held off for three months, fearing its cellular network could not handle the additional demand. Ironically, MMS has not been wildly popular on other mobile devices. According to ABI Research, MMS made up just 2.5 percent of all messages sent from phones worldwide last year. (link) But iPhone owners tend to make more use of multimedia features than other cellphone users. And many are likely to try it out the moment it becomes available. The feature is was unlocked though an AT&T update delivered to 3G and 3GS iPhones via iTunes. According to a note published Wednesday in DSLReports, AT&T was to begin sending mass text mailings to customers at 10 a.m. Eastern. However many iPhone owners got wind of Apple’s service notice before receiving any word from AT&T. The update took a few seconds. The MMS function seemed to work as advertised. The network did not crash.