The iPhone 5 is likely to be unveiled at Apple's special event on Wednesday, and more evidence has emerged to suggest that Apple will begin shipping the device on 21 September.

MacRumors reports that FedEx has sent a note to its employees in the US preparing them for a “surge volume” event from 21 to 24 September, which has been predicted to be the on-sale date of Apple's iPhone 5.

The note, which was sent to those expecting to attend a training session, reads: “Due to the upcoming “surge volume” event between Sep 21-24, this class has been postponed to the week of Nov 5-9 and you have automatically been moved to that class.”

While there is no specific mention of the iPhone 5 in the event, FedEx is one of Apple's main delivery companies in the US, so it seems likely that the new device will be the cause of the “surge volume”.

Apple sent out cryptic invitations for its 12 September event last week, and has since decorated the event's San Francisco location with a colourful banner that conceals iOS icons.

See also:

Apple's 9-pin dock connector cable for iPhone 5 shown in new photos
Apple may rely on celebrity for iPhone 5 launch, analyst