I assume you mean iMessages. If you have the Apple ID and password, you can access them on other Apple devices such as iPad/iPod. Not sure about Macs, but I would assume so. I don't think this would include SMS messages sent from non-Apple devices.
michelle7595, details are what paints the real picture. Text message content is maintained in Verizon message centers only for up to 10 days from receipt by Verizon Wireless. All requests for text message content must be made through an attorney or court and made exclusively to the Verizon Law Enforcement Resource Team at 800-451-5242. However, you can obtain text messaging details online at My Verizon, http://bit.ly/xB4iTc You will be provided with the date, time, and mobile numbers of the text messages sent/received on that iPhone 4 for the last 90 days. I apologize that for security purposes, actual content is not available to view online at our website.
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