What transactional email is#
Transactional email is triggered by a user action (receipts, password resets, alerts) and is exempt from most marketing consent rules. Marketing email promotes products and requires consent and unsubscribe links.
Why it matters#
Mixing the two on one domain or stream means a bad campaign can block password resets. Separating them protects critical mail.
How mailbox providers use it#
Gmail, Microsoft, and Yahoo combine authentication results, sender reputation, and recipient engagement into a placement decision made per message. Transactional email feeds directly into that model, and weaknesses compound with other signals.
How to measure the impact#
- Baseline inbox placement with seed tests before any change.
- Make one change at a time and hold volume steady.
- Re-test after 48 to 72 hours; provider models need time to update.
- Track Postmaster Tools and SNDS alongside your seed results.
Improving it#
- Send transactional mail from a dedicated subdomain (for example mail.yourdomain.com) or separate stream.
- Send marketing from a different subdomain (news.yourdomain.com).
- Keep promotional content out of transactional messages to preserve their exemption.
- Apply DMARC to the organizational domain so both subdomains are covered.
Frequently asked questions#
Do transactional emails need an unsubscribe link?
Not under CAN-SPAM if purely transactional. Gmail's bulk-sender rules still expect one-click unsubscribe for anything sent at volume, so many senders include it anyway.