Verify t-online.de addresses

T-Online (t-online.de, magenta.de) is Deutsche Telekom’s mail platform. Its SMTP servers answer probes ambiguously and block aggressively, so Kavik verifies existence through a dedicated Telekom login oracle instead.

How Kavik verifies T-Online

• Existence is answered by a Telekom login oracle: the same check Telekom’s own login flow performs, which distinguishes a real account from a nonexistent one.
• Account-lock states are surfaced separately from existence: a locked mailbox exists, and the result says so, instead of collapsing it into a false invalid.
• The oracle’s several login-view variants (OTP, customer number and combined views) are all recognized, since Telekom renders different flows to different clients.
• Telekom’s 554 connection-level blocks remain connection-level: they produce unknown, not invalid.

What the verdicts mean here

• Valid: the oracle confirms the account exists (lock state, if any, is reported alongside).
• Risky: ambiguous oracle state.
• Invalid: Telekom says the account does not exist.
• Unknown: connection-level block or throttle this time; never billed.

curl "https://api.kavik.email/api/v1/verify?email=jane@t-online.de" \
  -H "X-API-Key: eva_your_key"

See single verification for the full response shape.