FORMS · Published 2026-10-06 · Updated 2026-10-06 · SecureSMTP
Follow-up sequences
Send a series of emails over days, and add contacts to a sequence from the API.
A sequence is a list of steps. Each step sends one saved template after a delay. When you add a contact, the steps go out one after another.
Create a sequence
- Save the emails as templates first (
/app/templates). See Templates and variables. - Open Automations (
/app/automations). Enter a name, pick the site to send from, and click Create. - On the sequence page, add steps. Each step is a template and a delay in minutes. The first step’s delay counts from when the contact is added; each later step’s delay counts from the step before it.
- Click Activate. Only active sequences send.
Add a contact from the API
Copy the sequence ID from the Enroll via API box on the sequence page (it is also the last part of the page’s URL).
curl -X POST https://securessmtp.com/api/v1/sequences/enroll \
-H "x-securessmtp-api-key: $SECURESSMTP_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"sequence": "9b1f4c2e-5d6a-4e7b-8c9d-0e1f2a3b4c5d",
"email": "[email protected]",
"data": {
"name": "Ana"
}
}'- sequencestringrequired
- The sequence ID, up to 80 characters. The sequence must belong to the same account as the key.
- emailstringrequired
- The contact’s email address.
- dataobjectoptional
- Values for the template placeholders, for example
{{name}}. Keys up to 64 characters; values are strings, numbers or booleans.
| Response | Meaning |
|---|---|
{"ok":true,"result":"enrolled"} | Added. The first step is scheduled. |
{"ok":false,"result":"exists"} | This address is already going through this sequence. |
{"ok":false,"result":"no_steps"} | The sequence has no steps yet. |
Errors: 400 invalid_payload (bad JSON or a field failed validation), 404 sequence_not_found, and the usual key errors. They use a reason field. See the error catalogue.
You can also add someone by hand in the Enroll a recipient box on the sequence page.
How the steps are sent
- A job runs every minute and sends the steps that are due.
- Each step’s template is filled with the contact’s
data. - Steps are sent in relay mode from
[email protected]. The sender name is the sequence name. - Each step gets a one-click unsubscribe header and a visible unsubscribe link at the bottom. To place the link yourself, put
{{unsubscribe_url}}in the template; then no link is added. - If the address is suppressed or has unsubscribed from the site, the contact is taken out of the sequence and nothing more is sent.
- Pausing a sequence holds every step. When you activate it again, steps that came due in the meantime go out at the next run.
- Each step counts toward your monthly email count and shows in the email log with the source
automation.
The sequence list shows, for each sequence, the number of steps, the contacts still going through it and the contacts who finished.