Comment by burkaman

Of course they do, but you can't set official government apps to illegally delete messages after a week.

Edit: Seems like they are supposed to use Microsoft Teams https://dodcio.defense.gov/Portals/0/Documents/Library/Memo-.... Also -

> When mission needs or the effective conduct of DoD business cannot be adequately supported by Microsoft Teams Chat, SMS texting may be used in accordance with DoDI 8170.01. In such cases, a complete copy of the record must be forwarded to an official DoD electronic messaging account of the user within 20 days of the record's original creation or transmission in accordance with Section 2911 of Title 44 U.S.C, and Component processes. The complete copy of the record includes the content of the message and required metadata, and the record must be retrievable and usable in compliance with the applicable retention schedule approved by the Archivist of the United States. DoD Component heads shall ensure that DoD users are provided guidance on their Component's processes for forwarding complete copies of records originating in SMS texts.