How many cold email follow-ups before you start collecting spam complaints. I tracked complaint rates by sequence step across 90 days to find the real number
followup_count_nora · 2026-08-27 · 460 views
Everyone debates how many follow-up emails to send. Three? Four? Five? I stopped arguing about it and pulled real data from Google Postmaster Tools broken down by sequence step across 90 days of sending through 12 PuzzleInbox Google Workspace inboxes.
Here is what the complaint rate looked like by email position in a four-step sequence.
Email one: 0.09 percent spam complaint rate.
Email two: 0.14 percent.
Email three: 0.28 percent.
Email four: 0.51 percent.
The complaint rate on email four was more than five times higher than email one. And these complaints accumulate. They do not reset between campaigns. They sit on your sending domain and erode your reputation over time.
Google's published threshold is 0.3 percent before deliverability is affected. My email three was already nudging that boundary. My email four was clearly over it on busy weeks.
I cut to three emails. The result was not what I expected. Total positive replies per week barely changed. The prospects who were going to respond had mostly done so by email two. Email four was generating complaints from people who had already decided they were not interested and were annoyed enough to hit the spam button instead of just ignoring it.
The math on email four: it generated maybe 1 to 2 extra positive replies per week across my full campaign volume. It was generating enough spam complaints to measurably degrade domain reputation. That trade does not make sense.
My current sequence is three emails with deliberate gaps. Day one, day four, day nine. The day nine email is short, around 30 words, and reads as a genuine last check-in rather than a desperate fourth pitch. That tone makes a difference in complaint rate.
I still use Instantly for sequencing through these inboxes and the campaign-level reporting lets me see reply rate by step. But Postmaster is where the real signal lives. If you are not checking Postmaster domain reputation at least weekly, you are flying blind on the most important metric for long-term cold email performance.
Three is the number for most campaigns targeting most ICPs. If your email one and two are doing their job, a fourth email is mostly just an invoice you pay in domain reputation.