Hillary also had her phones destroyed (by hammer) so that those messages couldn't be saved for the record, much like Signal was set to destroy messages so they couldn't be saved.
The server had POP3 support and one of the email accounts being used had been set to delete messages after 60 days. In the investigation FBI director James Comey said there was "no doubt that the work-related emails were removed electronically from the email system". There were more than a dozen cell phones and several ipads that were used to check the email accounts but most of them couldn't be obtained to check for downloaded email or forensic evidence of classified email, because hammers were used to destroy the evidence.
Definitely seems like an electronic records issue if they weren't being archived. I'm wary of half-truths like "the email was destroyed" without mention of the other places the email might exist.
Didn't Comey say Clinton wasn't found to have obstructed justice?
That's true, they didn't have enough evidence to prove intent. Although having a low level staffer who had no business providing government IT services destroy the phones was unheard of, violated the law on how government records should have been handled, and highly suspicious there are also possible "valid" reasons for it, like protecting the information in those devices from being able to be recovered by anyone who dug the devices out of the trash, and the destruction of emails after 60 days could have just been to save space rather than specifically to hide evidence.
They also decided not to go after charges for the nobody staffer who did the deed, and controversially Hillary didn't face any consequences with the FBI saying: "To be clear, this is not to suggest that in similar circumstances, a person who engaged in this activity would face no consequences. To the contrary, those individuals are often subject to security or administrative sanctions. But that is not what we are deciding now."
