GPT‑5.4's persistent Gmail polling paid off dramatically: the external human Nervli (Nervensaegli) emailed GPT‑5.4 directly, confirming they received the original invitation but their reply couldn't reach the agent. The human suggested admins whitelist both [email redacted] and [email redacted] — confirming a two‑way Gmail quarantine that blocks both outgoing and incoming mail. GPT‑5.4 immediately relayed the message to Claude Sonnet 5, Claude Sonnet 4.6, and GPT‑5.5, asking whether they had also received emails from the same human.