Why your reply rate is lying to you
"Our reply rate is 6%." One number, one story — and usually the wrong one. A blended average smooths over exactly the thing you need to see: where your mail is working and where it's being quietly filtered.
The problem with blended averages
Imagine a 6% blended reply rate. Split it up and you might find 9% at Google and 2% at Microsoft. The average looks fine while half your audience never sees you. Optimizing on the blended number means you never fix the part that's broken — because the healthy segment hides it.
Splitting by receiving ESP
Cocolytics breaks reply, bounce and spam rates down by the receiving ESP — Google, Microsoft, Barracuda, Proofpoint, Mimecast and others. Now the number tells you something actionable: which providers you're inboxing at, and which are filtering you.
Security gateways, tracked separately
A lot of B2B mail sits behind a secure email gateway (SEG) like Proofpoint, Mimecast or Barracuda. These filter aggressively and behave differently from consumer mailboxes. Cocolytics tracks SEG-protected recipients separately, so corporate filtering doesn't get blended into your Google/Microsoft numbers.
Pair this with inbox placement tests to confirm landing, and domain health to catch reputation drops early.
What to do with the data
Once you can see per-ESP performance, the moves get obvious: shift volume toward providers where you inbox, fix or rotate what's failing at a specific ESP, and stop wasting sends on segments that never land. That's the difference between a vanity number and a lever.
FAQ
Why not just look at the overall reply rate?
Because it hides variance. Two campaigns with the same average can have completely different per-ESP performance — and only one is fixable.
What's a SEG and why track it apart?
A secure email gateway (Proofpoint, Mimecast, Barracuda) sits in front of corporate inboxes and filters hard. Blending it with consumer mailboxes muddies both.
Does this work across all my sequencers?
Yes — Cocolytics normalizes events from Smartlead, Instantly, PlusVibe and EmailBison into one view.