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MAILTIG

Deliverability

Why delivery does not equal inbox placement

A sent event means the provider accepted the message. Inbox placement is a different question, and no outreach tool can honestly promise it.

Deliverability in MAILTIG
A sent envelope that stops at a wall labelled inbox, showing they are not the same.

By MAILTIG editorial. Reviewed by Engineering (Deliverability lead (product source)) on 4 November 2026. Next review due 4 February 2027. 7 minute read.

When MAILTIG marks a campaign message Sent, the mailbox provider accepted it. That is delivery to the provider, not placement in a person's inbox.

Three different events

  1. Accepted by the provider. SMTP 250, Gmail API success, Graph sendMail success, ESP accepted. MAILTIG records Sent and debits one credit.
  2. Rejected or timed out. Connection errors refund the credit and retry later. Timeouts are recorded as Unknown because the provider may have accepted the message; MAILTIG does not resend.
  3. Placed in the inbox, promotions, or spam. The provider and the recipient's filters decide this. MAILTIG cannot observe it directly. Opens and clicks are noisy hints, not proof.

What MAILTIG actually controls

  • DNS checks for SPF, DKIM and DMARC (necessary, not sufficient)
  • Per-mailbox daily caps
  • Send windows and weekend flags
  • Warm-up between your connected mailboxes
  • A bounce circuit breaker (pause at ≥5% bounce after 20 sends)
  • One-click unsubscribe headers and a postal footer

None of those is an inbox promise. Anyone selling a guaranteed inbox is selling something MAILTIG will not write.