This is a frustrating but common issue—your ads are doing great, but email deliverability tanks, and with it, your revenue. Here’s why this can happen literally overnight, especially during high-intent campaigns like launches:
Top Reasons Your Email Deliverability Flopped Suddenly
1. You Hit a Spam Filter Algorithmically
2. Poor List Hygiene Before the Launch
Then ESPs assume you're not sending to willing recipients and punish your deliverability.
3. New Leads from Ads = Low Engagement
If your campaign suddenly hits thousands of these "lukewarm" leads, your email metrics tank (low open/click → high spam complaints).
4. Technical Setup Issues
Your SPF, DKIM, or DMARC records may not be fully set up or failed during launch.
Email sending platform IP reputation (especially if shared) could've been blacklisted or throttled.
Use tools like:
To scan your domain/IP and get a deliverability score.
5. Too Many Sends, Too Fast
If you scaled up from 5k to 50k sends overnight, Gmail and others will throttle you.
Especially if sent from a relatively new domain or IP (even if warmed up, sudden jumps look suspicious).
What You Can Do Now
Short-Term Fix:
Segment and re-engage only high-quality users: Send to people who opened/clicked in the last 30 days.
Use a plain-text style “apology email” from the founder, asking if they still want updates.
Warm up your IP again slowly, don’t blast.
Mid-Term Fix:
Authenticate your domain (SPF, DKIM, DMARC)
Build a welcome flow that primes new ad leads (with micro-commitments like quizzes, reply triggers).
Use multiple sender domains if needed (e.g., promo.brand.com for launches)