Send personalized welcome emails when a new Systeme.io contact opts in

Build an agent workflow that sends a personalized welcome email the moment a new contact opts into one of my Systeme.io funnels.

Trigger: an incoming webhook from Systeme.io. I will configure the outgoing webhook inside Systeme.io to fire on the Contact Created and Opt-In events. The webhook payload includes the contact's id.

When the webhook fires, the agent should:

1. Call Systeme.io's Get Contact operation with the contact id from the webhook payload to load the contact's email, first name, tags, and custom fields.

2. Infer which funnel or lead magnet the contact signed up for by reading the tags and custom field values. For example, a tag like guide-saas-pricing or a custom field like lead_magnet should shape the subject line and opening of the email.

3. Draft a short, warm welcome email addressed to the contact by first name when one is available. The email should reference the specific resource they signed up for, briefly set expectations for what is next (delivery of the resource, one or two follow-up emails, anything else they should know), and include a one-line invitation to reply if they have questions. Keep it human and conversational. Do not use em dashes. Do not fall back to a generic template that ignores the tags.

4. Send the email from my Gmail account using Gmail's Send a Message operation. Put the contact's email in the To field, use a plain-text body, and write a subject line that hints at the specific resource rather than a generic Welcome.

If the contact has no useful tags or custom fields yet, fall back to a brief generic welcome that thanks them for joining and tells them their resource is on the way, rather than skipping the email entirely.

The email should sound like it is coming from me personally, not from a marketing system.

Additional information

What does this prompt do?

Watches Systeme.io for new contacts and opt-ins and reacts within seconds.
Reads the contact's tags and custom fields to figure out which funnel or lead magnet they signed up for.
Writes a short, human welcome email that references that specific resource and sets expectations for what comes next.
Sends it from your Gmail so it lands as a personal note, not a template blast.

What do I need to use this?

A Systeme.io account where you can create an API key and set up an outgoing webhook.
A Gmail or Google Workspace account you want the welcome email to send from.
Funnels or forms that apply consistent tags, so the agent can tell what each new contact signed up for.

How can I customize it?

Adjust the tone, length, or signature so it matches how you actually write.
Map specific tags to specific welcome angles, like a free guide versus a webinar registration.
Have the agent leave each email as a draft for you to review, instead of sending automatically.
Add a CC, BCC, or internal Slack ping when a high-value contact comes in.

Frequently asked questions

Does this run for every new Systeme.io contact, or only opt-ins?

You choose. Systeme.io can send an outgoing webhook for Contact Created, Opt-In, or both, and the agent runs once per event you subscribe to.

How does the agent know which funnel or lead magnet someone joined?

It reads the tags and custom fields on the new contact. Systeme.io applies funnel tags automatically when someone opts in, so as long as your tag names are descriptive, the agent has what it needs.

Will the emails sound like templates?

No. Each email is drafted fresh from the contact's actual tags and context. They are short, conversational, and reference the specific resource the person signed up for.

Can I review emails before they go out?

Yes. Tell the agent to leave each welcome as a Gmail draft instead of sending, and you can sign off on them in your drafts folder.

What happens if the contact has no tags yet?

The agent falls back to a friendly generic welcome that thanks them for joining and promises their resource is on the way, so the lead still gets a fast personal reply.