Email QR Code API Guide

An email QR code encodes a mailto: URI. Scanning it opens the phone's default mail app with the recipient address — and optionally the subject line and message body — already filled in. The user reviews and sends.

As with SMS codes, there is no web service in this flow, so an email qr code api search is really asking one of two questions: what payload format do I encode, or what library do I call to generate the image? Both are answered below, along with a plain statement of what SMLLR's own REST API does and does not do, because that distinction is where most content on this topic quietly misleads.

The modern, near-universally supported format is the mailto: URI, defined by RFC 6068:

mailto:sales@example.in?subject=Bulk%20order%20enquiry&body=Hi%2C%20I%20saw%20your%20QR%20code

The rules that matter in practice:

• The address comes immediately after mailto:, with no slashes.
• The first parameter is introduced with ?, every subsequent one with &.
• Subject and body must be percent-encoded. Spaces become %20, commas %2C, newlines %0A. An unencoded space or ampersand is the single most common cause of a truncated subject line.
• cc and bcc are also supported: ?cc=support@example.in&subject=....

SMLLR builds exactly this shape when you create an Email QR code — the address is URI-encoded, and subject and body are each percent-encoded before being appended as parameters.

The older MATMSG: format (MATMSG:TO:a@b.in;SUB:Subject;BODY:Message;;) is a legacy Denso Wave convention. Some dedicated scanner apps still parse it, but native phone cameras — where the overwhelming majority of Indian scans happen — handle mailto: far more reliably. Use mailto:.

Email payloads fail in specific, repeatable ways. The ones worth guarding against:

• Unencoded special characters. An & inside your body text will be read as a parameter separator and silently truncate everything after it. Always encode the full subject and body, never just the spaces.
• Line breaks. Use %0A for a newline. Raw newlines in a QR payload are handled inconsistently and can break the URI entirely.
• Non-Latin scripts. Hindi, Tamil or Bengali text in a subject line must be UTF-8 percent-encoded, which expands it substantially — a short Devanagari subject can add a surprising number of characters to the payload and push the code to a higher, denser QR version.
• Long bodies make dense codes. A pre-filled body of two or three sentences can easily push the payload past 250 characters. Our data capacity guide covers what that does to scan reliability; the short version is that a long body is a scanning problem, not just an aesthetic one.
• Desktop vs mobile. On a phone with a configured mail app, mailto: works cleanly. On a desktop with no default mail client set, it can do nothing at all — worth remembering if the code appears on anything that gets screenshotted and opened later.

For bulk generation — one code per branch, per salesperson, per product line — build the payload and encode it in your own backend.

Python:

import qrcode
from urllib.parse import quote

def email_qr(to: str, subject: str, body: str, out_path: str):
    payload = f"mailto:{to}?subject={quote(subject)}&body={quote(body)}"
    qrcode.make(payload).save(out_path)

email_qr("sales@example.in", "Bulk order enquiry", "Hi, I saw your QR code", "branch_delhi.png")

Node.js:

const QRCode = require('qrcode');

const subject = encodeURIComponent('Bulk order enquiry');
const body = encodeURIComponent('Hi, I saw your QR code');
const payload = `mailto:sales@example.in?subject=${subject}&body=${body}`;
await QRCode.toFile('branch_delhi.png', payload, { errorCorrectionLevel: 'Q' });

Note quote and encodeURIComponent on the subject and body but not on the whole URI — encoding the entire string would escape the ? and & that make the parameters work. Our Python QR code API guide goes further into library choice and output formats.

A raw mailto: QR code is invisible to analytics for the same reason an SMS code is: the scan opens a local app without contacting any server. No scan count, no timestamp, no device split, no per-placement attribution.

For an email code specifically this hurts more than it might seem, because email enquiries are usually a higher-value action than a click — a bulk order enquiry, a distributor application, a B2B lead. Not knowing which trade-show banner, which catalogue page or which dealer counter produced them makes the channel impossible to optimise.

The second problem is permanence. Change the receiving address — a salesperson leaves, a department is restructured, sales@ becomes orders@ — and every printed code routes mail to a dead mailbox. There is no fix without a reprint.

Stated precisely:

In the dashboard, Email is a QR type available from the Starter plan (₹499/month). Enter the address, subject and body; SMLLR builds and encodes the mailto: payload.

The SMLLR REST API is read-only reporting only. Seven GET endpoints — summary, QR list, QR detail, campaign list, campaign detail, client list, client detail — on the Premium plan (₹14,999/month), limited to 60 requests per minute per key. There is no endpoint to create, edit or delete a QR code, and no endpoint that sends email.

It is worth separating two things that sound similar. SMLLR's Email Marketing feature — campaign sending to your captured leads, backed by a verified sending domain — is a real, shipped product surface available on the Pro plan (₹4,999/month) and up, operated from the dashboard. It is not exposed through the public API, and it is a completely different thing from an email QR code, which just opens the scanner's own mail app. Our email marketing setup guide covers that feature; this post is about the QR payload.

The public API also never returns Lead Hub contact data — no names, emails, phone numbers or consent records — by design.

If the goal is "make it easy to email us and let me measure it," the better construction is a dynamic QR code pointing at a contact page that carries the mailto: link as a button, or a proper lead capture form.

With the redirect in front, you get scan counts, timestamps, device and city breakdown, and per-code attribution — so you can finally tell whether the catalogue insert or the trade-show banner produced the distributor enquiries. And because the destination is editable, a change of receiving address is a dashboard edit rather than a reprint.

If you go a step further and use a lead capture gate (Lead Hub, Pro plan, ₹4,999/month), the enquiry lands in a structured dashboard with source attribution and consent recorded, rather than as an unstructured email in a shared inbox that nobody can report on.

Create your QR code on SMLLR — the Email type for a direct code, or a dynamic URL code when the enquiry is worth measuring.