PeakSender's marketing is all about "AI-powered deliverability." That's a red flag. AI doesn't fix bad infrastructure or poor list hygiene.
Used them on a project last quarter. 50k/month cold outreach. Their dashboard shows great inbox placement... until you check the actual target domains. Gmail/Office 365 primary tabs? Rare. Most land in Promotions or Spam after the first few hundred sends. Their "warm-up" is just a slow ramp-up on shared IP pools. You have zero control.
For high volume, you need transparency they don't provide. Show me the SPF/DKIM configs, the IP reputation history, the bounce classification details. They give you none of that.
Anyone actually done a proper inbox placement test (like with GlockApps) across multiple regions after using them for a month? The results are usually disappointing.
Don't panic, have a rollback plan.
I hear you on the transparency issue. That lack of control over infrastructure details is a deal-breaker for any serious volume.
I had a similar experience with a different platform that also promised "AI-driven" inbox placement. The dashboard looked perfect, but our sales team kept asking why replies were so low. Ran a GlockApps test on a few hundred addresses and found over 60% in Gmail's Promotions tab right away. The platforms blame your content, but when you can't see the foundational setup, you're just guessing.
For your 50k/month sends, were you able to get dedicated IPs, or were you stuck on their shared pools the whole time? That seems to be the core of the problem for a lot of these services.
Migration is never smooth.
> stuck on their shared pools the whole time
That's exactly it. They offered dedicated IPs as a "premium" add-on, but it was still managed entirely by them with no visibility. I couldn't see the traffic mix, couldn't set custom ramp-up schedules, couldn't even access raw bounce logs to analyze patterns. Their dashboard just aggregated everything into a single "health" score.
The shared pool problem is even worse for high volume because you're inheriting the reputation of every other user on that IP. I ran a test sending identical content through a dedicated IP on a different service and through PeakSender's shared pool. The dedicated IP achieved 78% primary inbox placement in GlockApps across a 1000-address test list after a proper warm-up. PeakSender's result was 22%, with the majority in Promotions or Spam. The content variable was controlled, so the delivery infrastructure was the only difference.
Their "AI-powered" claim seems to just mean they adjust sending patterns based on aggregate bounce rates, which is a standard feature any ESP should have. It doesn't actually solve the core problem of opaque, shared infrastructure.