SubsiMail
Why self-host Pricing Docs Changelog Support FAQ Log in Get started
Log in Get started

← Back to Support

My open rates dropped and emails are landing in spam

#4 Resolved
Amanda P. 225 days ago

Something changed about two weeks ago — my open rate went from around 35% down to under 5%, and a few contacts told me they found my email in their spam folder. I haven't changed my content or sending volume. What should I check first?

Carol Wright Staff 225 days ago

Sorry to hear that — a sudden drop like this is almost always one of a few things. Can you confirm:

  • Are SPF, DKIM, and DMARC all still passing for your sending domain? (You can check with a tool like mail-tester.com.)
  • Did your sending volume or frequency change recently, even slightly?
  • Has your bounce rate crept up? A rising bounce rate is one of the fastest ways to get flagged.

If none of those changed, it's also worth checking whether your domain or IP shows up on any blacklists (mxtoolbox.com has a free blacklist checker).

Amanda P. 224 days ago

Ran mail-tester — SPF/DKIM/DMARC all pass. Bounce rate is only up slightly (2% vs 1.5% before). But I did notice I switched from sending in small batches throughout the day to sending everything at once in the morning, to save time.

Carol Wright Staff 223 days ago

That's almost certainly it. Sending a large batch all at once looks very different to ISPs than the same volume spread out — it's a classic spam-trigger pattern, even from an otherwise healthy domain. Go back to spreading sends out (a few hundred per hour rather than all at once), and your reputation should recover over the next 1–2 weeks. If open rates don't start climbing back within that window, let us know and we'll dig into your specific ISP-level delivery logs.

This ticket has been resolved. Its author or SubsiMail staff can reopen it to reply further.

Other tickets

Resolved Is there a way to pause a campaign via the API?
Justin C. 1 reply
Resolved Rate limits — how many requests per minute are allowed?
Jacob W. 1 reply
Resolved Does deleting a contact via API also delete their event history?
Susan L. 1 reply
Closed DKIM check keeps failing on Namecheap too
Lisa T. 2 replies
Resolved How do I change my account's primary email address?
Christopher C. 1 reply

SubsiMail

The self-hosted alternative to Mailshake.

Documentation Setup guides Changelog Support Pricing Affiliates Terms of Service Privacy Policy Sitemap

Compare

vs. Instantly vs. Smartlead vs. lemlist vs. Apollo

Solutions

For agencies For recruiters

© 2026 SubsiMail.

We use Google Analytics to understand traffic to this site. It only runs if you accept -- see our Privacy Policy.