Feeling overwhelmed by your email marketing? You’re not alone. Many businesses grapple with juggling a growing list of contacts, verifying each email address, and ensuring no one domain (like gmail.com) gets bombarded all at once. There’s a solution—an automated workflow that leverages Google Sheets, Gmail, and an external SMTP service for truly unlimited sends.

  • Why Google Sheets?
    Because it’s user-friendly, easy to share with your team, and ideal for managing contact lists.
  • Why an external SMTP?
    Gmail alone has daily sending limits, which can be a deal-breaker if you’re scaling up to thousands (or tens of thousands) of emails. By hooking into a service like SendUnlimitedEmail.com, you can go beyond Gmail’s strict cap and still get a high deliverability rate.
  • What about validation and domain spacing?
    To keep your emails from going straight to spam, you need to validate each email address (removing invalid or duplicated entries) and space out sends to the same domain. That way, you aren’t accidentally blasting ds50 @gmail.com addresses in a row.

Ready for the Full Step-by-Step Solution?

We’ve prepared a detailed tutorial that covers:

  1. Google Sheets Setup (removing duplicates, empty cells)
  2. Email Validation (regex + DNS lookup)
  3. Domain Spacing (round-robin shuffle logic)
  4. Cleaning Addresses (strip digits if needed)
  5. Third-Party SMTP Integration (for unlimited sends)

Dive into the comprehensive guide here:
Automate Email Marketing with Gmail, Google Sheets & Third-Party SMTP

In that full tutorial, you’ll find:

  • Detailed code to copy/paste into your Google Apps Script.
  • Common errors (like timeouts or invalid DNS checks) and their solutions.
  • FAQ on scheduling, daily limits, and hooking into external SMTP credentials.