We'd love to keep your data forever, but our servers set limitations on storing certain kinds of data.
String's data retention policy is as follows:
SMS text messages are stored in your inbox indefinitely for the life of your account.
MMS attachments (pictures, videos, etc) are deleted after 730 days or 2 years.
If you delete these messages, we are unable to restore them.
Voicemails are stored for 90 days, but can also be downloaded across devices.
For any attachments that are absolutely critical, we always recommend downloading and backing up in your own personal storage elsewhere.