Do shared IPs always perform worse?

Shared IPs have a bad reputation (pun intended). The assumption is that you're sharing sending infrastructure with strangers, one of them behaves badly, and your deliverability tanks along with theirs. That does happen. But it's not the whole story.

Shared IPs don't automatically perform worse than dedicated ones. A well-managed shared pool at a reputable ESP can actually carry stronger reputation than a dedicated IP you just started warming. That's because the pool already has history, volume, and established trust with mailbox providers. A fresh dedicated IP has none of that.

The real question isn't "shared or dedicated." It's whether your shared pool is being actively managed.

What good pool management looks like:

• The ESP removes senders with high bounce rates and complaint rates quickly.
• They segment by sender type (transactional vs marketing, high volume vs low volume).
• They monitor blocklisting and delist proactively.
• They don't let new or unverified senders share IPs with established ones.

Bad pool management is the opposite. Anyone gets in, complaints pile up, and the shared reputation slowly degrades. That's when you feel the damage even if your own sending is clean.

How to check if your shared pool is healthy:

Start by running your sending IP through a blocklist checker. You can use our free blocklist checker to see if your IP is flagged anywhere. If it shows up on major lists like Spamhaus, that's a signal your pool has problems that aren't yours to own.

Then look at your sending metrics in your ESP dashboard:

• Delivery rate: anything below 97% on a clean list is worth investigating.
• Spam complaint rate: above 0.1% to Gmail consistently is a pool concern or a list concern. Either way, act on it.
• Soft bounces spiking: if your soft bounce rate jumps without any change to your list, the IP may be getting temporarily rate-limited or blocked.

Now you can also pull the headers on a test email (our free email header analyzer makes that readable) to see exactly which IP sent your message, then check that IP independently.

When to actually switch:

And if you're seeing persistent deliverability drops, your blocklist results are bad, and your ESP can't tell you what they're doing about pool health, that's the real flag. For moderate-volume senders (under a few hundred thousand emails per month), a quality shared pool is usually fine. At higher volumes, or if you're in a reputation-sensitive industry, a dedicated IP might make sense, but only if you can warm it properly.

If things are breaking and you're not sure where to start, our SOS hotline is free. We'll help you figure out if it's the pool, your list, or something else entirely.