Transactional and marketing email, defined
Transactional email is sent because of something a person did or something that happened in their account: a password reset, a sign-in code, a receipt, a shipping update, a security alert. It goes to one person, at the moment it's needed, and they expect it.
Marketing email promotes a product, service or piece of content. Your team decides when it goes out and who gets it, usually a list or a segment. Newsletters, launches, offers and win-back campaigns all fall here.
The line matters for three reasons: the law treats the two differently, mailbox providers expect different things from them, and a problem in one stream shouldn't slow down the other.
Transactional vs marketing emails, side by side
| Transactional | Marketing | |
|---|---|---|
| Trigger | TransactionalAn action or event in one account | MarketingYour team's schedule |
| Recipients | TransactionalOne person per event | MarketingA list or segment |
| Timing | TransactionalNow; late is often useless | MarketingPlanned; minutes rarely matter |
| Main purpose | TransactionalComplete, confirm or update something | MarketingPromote something |
| Unsubscribe | TransactionalDepends on the rules that apply | MarketingExpected, often one-click |
| Typical sender | TransactionalYour app, over SMTP or an API | MarketingAn email marketing platform |
How the law draws the line (a US example)
Rules differ by country, so treat this as an example, not legal advice. In the US, the FTC's CAN-SPAM guide sorts content into commercial content, transactional or relationship content, and other content. What decides a message is its primary purpose.
Content is transactional or relationship when it consists only of things like:
- facilitating, completing or confirming a transaction the recipient already agreed to;
- warranty, recall, safety or security information about something they bought;
- notice of a change in the terms, features or standing of a membership, subscription or account, or regular account balance information;
- information about an employment relationship or benefits;
- delivering goods or services as part of an agreed transaction.
The FTC says these categories are read narrowly. An ongoing customer relationship doesn't make every email transactional. Messages whose primary purpose is transactional or relationship are exempt from most of CAN-SPAM's provisions, though their routing information must still be truthful.
What Gmail and Yahoo expect from each
Google requires senders of more than 5,000 messages a day to Gmail accounts to support one-click unsubscribe in marketing and subscribed messages, with a clearly visible unsubscribe link in the body. Yahoo asks bulk senders for a working one-click list-unsubscribe header on marketing and subscribed messages, and to honor unsubscribes within 2 days.
Authentication, DNS and spam-rate requirements apply to all of your mail, transactional included. The full checklist is in Gmail and Yahoo sender requirements.
Why keep transactional and marketing emails apart
Yahoo's sender guidance recommends separating email types by IP or DKIM domain, and not sending bulk or marketing email from the IPs you use for transactional mail. Each IP and DKIM domain builds its own reputation.
The practical effect: if a campaign draws complaints, your password resets and sign-in codes shouldn't pay for it. Many teams use a separate sending subdomain for each stream, for example mail.acme.com for the app and news.acme.com for campaigns, each with its own SPF, DKIM and DMARC records. See SPF, DKIM and DMARC explained.
Example subdomains · illustrative.
Mixed messages: a receipt with a promotion
Plenty of emails mix both. Under the FTC's approach, a message counts as commercial if a reader of the subject line would likely think it's an ad, or if the transactional part doesn't appear mainly at the beginning. If you add a promotion to a receipt, keep the order details first and the promotion short. If the promotion is the point, send it as a campaign instead.
Example email · illustrative. Not legal advice.
How tinyRelay and tinyEmail split the work
tinyCo makes one product for each lane, on the same email delivery infrastructure:
- tinyRelay sends the email your app triggers, over an SMTP relay or a transactional email API. Every SEND, DELIVERED, BOUNCED, OPEN, CLICK, UNSUBSCRIBE and SPAM event comes back to your endpoint as a signed webhook, with your metadata attached.
- tinyEmail is a complete email marketing platform with a REST API for campaigns, audiences, senders, templates and reporting.
Use tinyRelay on its own, or alongside tinyEmail. Read how tinyEmail and tinyRelay fit together, or the tinyRelay API documentation.
Sources
- FTC, CAN-SPAM Act: A Compliance Guide for Business: ftc.gov
- Google, Email sender guidelines: support.google.com/a/answer/81126
- Yahoo Sender Hub, Sender Best Practices: senders.yahooinc.com/best-practices