How long are text messages stored after being deleted?
Phones used by average people on major networks like Verizon and AT&T (the carriers who support the iPhone) only keep text messages for a few days. AT&T for instance, only keeps a deleted text message for 72 hours. Verizon keeps deleted SMS messages for up to 10 days.
How long can text messages be retrieved?
He states that messages up to two years old can be recovered, although this happens rarely. More often, the texts must be a year old or younger to be retrieved.