Back up MailOptin opt-ins to Google Sheets
MailOptin captures email subscribers through popups, sidebar widgets, and exit-intent forms. LeadToSheet creates a real-time Google Sheets backup of every opt-in so you never lose a lead, even if your email platform has sync issues.
CMS: WordPress
Overview
MailOptin specializes in email opt-in forms with popups, slide-ins, in-post forms, exit-intent triggers, and A/B testing. It connects to Mailchimp, ConvertKit, ActiveCampaign, and more. LeadToSheet adds a Google Sheets safety net, giving you a platform-independent record of every subscriber with attribution data your email platform does not store.
Implementation checklist
- 1
Install the LeadToSheet snippet site-wide
MailOptin forms can appear anywhere on your site (popups, sidebars, in-content). A global footer snippet ensures every opt-in location is covered.
LeadToSheet snippet
<script>(function(w,d,s,u,k,e){if(w.__formsync){return}w.__formsync={q:[],k:k,endpoint:e};var js=d.createElement(s);js.src=u;js.async=1;js.onload=function(){w.__formsync.init&&w.__formsync.init({ clientKey:k })};d.head.appendChild(js);})(window,document,'script','https://www.leadtosheet.com/sdk.min.js','YOUR_CLIENT_KEY','https://www.leadtosheet.com/api/ingest');</script> - 2
Trigger each opt-in type
Test a popup, a sidebar widget, and an in-post form. Each opt-in type fires a standard form submission that LeadToSheet captures.
Tip: Use an incognito window to trigger exit-intent popups during testing.
- 3
Verify A/B test variants both sync
If you run A/B tests on opt-in forms, submit through both variants. LeadToSheet captures the page URL and form variant so you can compare conversion data in Sheets.
Customization ideas
Track which opt-in type converts best
LeadToSheet records the form element context (popup, sidebar, inline). Build a pivot table in Sheets to compare conversion rates across opt-in placements.
Create an email platform failover
If MailOptin's connection to your email platform drops, your Google Sheet becomes an instant backup. Re-import the missed subscribers from Sheets once the connection is restored.
Enrich opt-ins with UTM and referrer data
MailOptin forms rarely capture marketing attribution. LeadToSheet automatically appends UTM parameters and referrer URLs so you know exactly which campaign drove each subscriber.
Troubleshooting
Popup form submissions not captured
MailOptin popups inject into the DOM dynamically. LeadToSheet uses MutationObserver to detect new forms. If capture fails, ensure no other script is destroying and recreating the popup DOM on each trigger.
Exit-intent form fires but no row appears
Some exit-intent implementations redirect the page before the sync completes. LeadToSheet uses sendBeacon (with fetch as a fallback) for delivery, which handles most redirect scenarios, but extremely fast redirects may prevent capture.
Duplicate entries from MailOptin and LeadToSheet
LeadToSheet and MailOptin's native integrations operate independently. If you see duplicates in your email platform, the issue is on the email platform side. Your Sheet will have exactly one row per opt-in.
Resources
Frequently asked questions
- Does LeadToSheet replace MailOptin's email platform integrations?
- No. LeadToSheet creates a Google Sheets copy of each opt-in. Your MailOptin connections to Mailchimp, ConvertKit, or other platforms continue working as configured.
- Can I see which A/B test variant a subscriber came from?
- LeadToSheet captures the page URL and form context. If MailOptin uses different form IDs or class names for variants, those appear in the row metadata for filtering.
- Will LeadToSheet slow down my popups?
- The SDK loads asynchronously and does not block DOM rendering. Your popups and exit-intent triggers fire at the same speed with or without LeadToSheet.