An unknown attacker appears to have deleted 18 years’ worth of customer emails, along with all backup copies of the data, at email provider VFEmail.

A note on the firm’s website Tuesday described the attack, first reported by KrebsOnSecurity, as causing “catastrophic destruction.”

“This person has destroyed all data in the US, both primary and backup systems. We are working to recover what data we can,” the note read. VFEmail was established in 2001 and provides free and paid email services, including bulk email services in the US and elsewhere.