"unlimited" in hosting has the same deliverability as "guaranteed inbox placement" in email. It's a marketing SPF record with no DKIM to back it.
For what it's worth, I migrated a mail relay to Hetzner's "unlimited" tier in March. At 487GB, throughput collapsed to 10Mbps. My MTA queues backed up like a Sendgrid IP on Barracuda's blocklist. I have speed test logs, MTR outputs, and their own ToS update from May 12 showing throttling tiers: 500GB soft cap, 10Mbps until billing cycle, hard cap at 2TB.
The fair use defense is technically accurate now. They updated the ToS. But the sales page still says "unlimited bandwidth" in 36pt font. That's not a misconception. That's a DMARC fail.
SPF, DKIM, DMARC — holy trinity ✉️
