Most of them will get lots of SMS and MMS, some messages need to keep. SMS Backup plus is android app that will help you to back up your SMS into your Gmail account and restore later.
You can easily install SMS Backup plus in to your mobile after the installation you must enable IMAP in Gmail settings. After connected your Gmail account, SMS Backup plus will ask you to perform a first sync. After the backup process is complete you can see your messages in your Gmail account under the SMS label.
If you wish to restore messages back to your phone tap “Restore”. By default all messages stored on Gmail will be restored. You can safely restore to a phone which has already message stored on it, SMS Backup plus will skip the restore of already existing messages.