This comparison gets confused because “email service provider” covers a huge range of products. Some services do everything – campaigns, templates, infrastructure, analytics, and governance tools. Some do just infrastructure. The question is about what each layer does.
When you use Mailgun or SendGrid, you’re getting SMTP capability. That’s a sending channel. You can send email through their servers. That’s useful. But it’s not the same as managed infrastructure.
SMTP Gives You Sending Ability, Not Inbox Management
SMTP is like having a post office. You can drop off mail. They move it through the system. But they don’t control the reputation of the mail or the credibility of the sender. You’re just renting the ability to transmit.
Most traditional ESPs run shared IP pools. Thousands of senders share the same infrastructure. That’s efficient for the provider. It’s terrible for your reputation. Your success is tied to the behavior of strangers using the same pool. If someone else on your IP pool sends spam, Gmail sees reputation decline. Your legitimate mail gets throttled as collateral damage.
Here’s a real scenario: You’re using SendGrid’s shared pool. You have good engagement. Someone else on your IP pool gets compromised and starts sending spam. Within hours, Gmail starts rate-limiting the entire IP. Your legitimate sends start bouncing. Your bounce rate jumps noticeably. You have no control and no visibility into what happened on the IP or how to fix it. SendGrid’s support says “we’re monitoring the situation.” You’re dead in the water.
Because it’s shared, the vendor has limited ability to maintain IP reputation. They’re constantly rehashing degraded IPs and replacing them. They can do reputation scoring and monitoring, but they can’t build compound reputation. They’re managing decline, not building credibility. The best they can do is rotate out bad IPs before they fully degrade. You’re always on a new IP, always proving yourself, always burning reputation credibility.
If you’re sending high volume from a shared pool, you’re fighting uphill against the reputation damage from lower-quality senders on the same infrastructure. That’s not a level playing field.
The Cold-Only Traffic Problem
ESPs like Mailgun and SendGrid were built for transactional email and marketing campaigns – high engagement, warm audiences, strong content. They work great for that. If you’re sending password resets or order confirmations to people who opted in, shared ESP infrastructure works fine. Recipients are expecting your mail. ISPs know it’s legitimate because engagement is high.
Cold outreach is different. Your first send to an address is from unknown infrastructure. ISPs don’t know you yet. They’re evaluating you. Shared infrastructure with a fragmented sender base is exactly what looks suspicious in that scenario. An ISP sees an IP sending transactional mail one minute and cold outreach mail the next. Different sender identities. Different sending patterns. Different recipient expectations. That’s not coherent. That’s fragmented. That triggers filtering.
Building IP reputation for cold outreach requires consistency and intentionality. The same IPs sending traffic from the same domain, building a track record over time. Shared pools don’t support that. They’re constantly rotating senders, mixing traffic, and managing reputation degradation. One domain is sending legitimate order confirmations. The next is sending cold sales email. The fragmentation is visible to ISPs and they penalize it.
That’s why specialized cold email services and managed infrastructure exist – because general-purpose ESP infrastructure doesn’t solve the cold outreach problem. General-purpose ESPs optimize for volume and efficiency. Cold outreach optimization requires dedicated infrastructure, intentional domain strategy, and reputation building over time.
Continuous Rehabilitation vs. Earned Trust
When you use a shared pool, the vendor is continuously rehabilitating IP reputation. They monitor degradation, they warm new IPs, they replace blacklisted ones. They’re fighting entropy. It’s like trying to keep a pool clean while constantly adding dirty water. You’re always a few bad senders away from collapse.
With managed infrastructure, we build reputation that doesn’t degrade because we’re intentional about who sends from it and how. We’re not adding random traffic. We’re carefully managing our infrastructure for a specific use case – credible cold outreach at scale. We’re selective about what we allow on each IP. We monitor closely. We intervene immediately when issues emerge. The reputation compounds because we’re building it carefully, not fighting it constantly.
Here’s the difference in approach: A shared pool vendor can detect reputation decline, but they can only respond by rotating IPs. The underlying problem (too many senders, mixed traffic, fragmented identity) never gets solved. They’re fighting the symptom.
Managed infrastructure solves the root problem. Fewer domains means less fragmentation. Intentional sending means reputation compounds instead of degrading. Careful monitoring means we catch issues before they become crises. One approach is about managing decline. The other is about building trust that compounds.
A Note on Dedicated IPs
Some teams consider using their own dedicated IPs instead of shared pools. Dedicated IPs do isolate you from other senders’ reputation issues, which is an advantage. But there are important tradeoffs: warming up a dedicated IP takes significant time – much longer than most expect. You may need multiple dedicated IPs to reach necessary volume, which multiplies your infrastructure burden. You’ll need to split traffic among them while each builds reputation.
Managed infrastructure avoids these problems by giving you pre-warmed, carefully distributed infrastructure that’s already proven itself.
We’d love to learn more about your business, email deliverability and outreach goals, and see if we might be able to help.
Whether you have questions about what we do, how Protocol works, or you’d just like to pick our brains on some of our best practices, we’d be happy to chat.
Schedule a call with our Revenue Director, Chrisley Ceme.
This comparison gets confused because “email service provider” covers a huge range of products. Some services do everything – campaigns, templates, infrastructure, analytics, and governance tools. Some do just infrastructure. The question is about what each layer does.
When you use Mailgun or SendGrid, you’re getting SMTP capability. That’s a sending channel. You can send email through their servers. That’s useful. But it’s not the same as managed infrastructure.
SMTP Gives You Sending Ability, Not Inbox Management
SMTP is like having a post office. You can drop off mail. They move it through the system. But they don’t control the reputation of the mail or the credibility of the sender. You’re just renting the ability to transmit.
Most traditional ESPs run shared IP pools. Thousands of senders share the same infrastructure. That’s efficient for the provider. It’s terrible for your reputation. Your success is tied to the behavior of strangers using the same pool. If someone else on your IP pool sends spam, Gmail sees reputation decline. Your legitimate mail gets throttled as collateral damage.
Here’s a real scenario: You’re using SendGrid’s shared pool. You have good engagement. Someone else on your IP pool gets compromised and starts sending spam. Within hours, Gmail starts rate-limiting the entire IP. Your legitimate sends start bouncing. Your bounce rate jumps noticeably. You have no control and no visibility into what happened on the IP or how to fix it. SendGrid’s support says “we’re monitoring the situation.” You’re dead in the water.
Because it’s shared, the vendor has limited ability to maintain IP reputation. They’re constantly rehashing degraded IPs and replacing them. They can do reputation scoring and monitoring, but they can’t build compound reputation. They’re managing decline, not building credibility. The best they can do is rotate out bad IPs before they fully degrade. You’re always on a new IP, always proving yourself, always burning reputation credibility.
If you’re sending high volume from a shared pool, you’re fighting uphill against the reputation damage from lower-quality senders on the same infrastructure. That’s not a level playing field.
The Cold-Only Traffic Problem
ESPs like Mailgun and SendGrid were built for transactional email and marketing campaigns – high engagement, warm audiences, strong content. They work great for that. If you’re sending password resets or order confirmations to people who opted in, shared ESP infrastructure works fine. Recipients are expecting your mail. ISPs know it’s legitimate because engagement is high.
Cold outreach is different. Your first send to an address is from unknown infrastructure. ISPs don’t know you yet. They’re evaluating you. Shared infrastructure with a fragmented sender base is exactly what looks suspicious in that scenario. An ISP sees an IP sending transactional mail one minute and cold outreach mail the next. Different sender identities. Different sending patterns. Different recipient expectations. That’s not coherent. That’s fragmented. That triggers filtering.
Building IP reputation for cold outreach requires consistency and intentionality. The same IPs sending traffic from the same domain, building a track record over time. Shared pools don’t support that. They’re constantly rotating senders, mixing traffic, and managing reputation degradation. One domain is sending legitimate order confirmations. The next is sending cold sales email. The fragmentation is visible to ISPs and they penalize it.
That’s why specialized cold email services and managed infrastructure exist – because general-purpose ESP infrastructure doesn’t solve the cold outreach problem. General-purpose ESPs optimize for volume and efficiency. Cold outreach optimization requires dedicated infrastructure, intentional domain strategy, and reputation building over time.
Continuous Rehabilitation vs. Earned Trust
When you use a shared pool, the vendor is continuously rehabilitating IP reputation. They monitor degradation, they warm new IPs, they replace blacklisted ones. They’re fighting entropy. It’s like trying to keep a pool clean while constantly adding dirty water. You’re always a few bad senders away from collapse.
With managed infrastructure, we build reputation that doesn’t degrade because we’re intentional about who sends from it and how. We’re not adding random traffic. We’re carefully managing our infrastructure for a specific use case – credible cold outreach at scale. We’re selective about what we allow on each IP. We monitor closely. We intervene immediately when issues emerge. The reputation compounds because we’re building it carefully, not fighting it constantly.
Here’s the difference in approach: A shared pool vendor can detect reputation decline, but they can only respond by rotating IPs. The underlying problem (too many senders, mixed traffic, fragmented identity) never gets solved. They’re fighting the symptom.
Managed infrastructure solves the root problem. Fewer domains means less fragmentation. Intentional sending means reputation compounds instead of degrading. Careful monitoring means we catch issues before they become crises. One approach is about managing decline. The other is about building trust that compounds.
A Note on Dedicated IPs
Some teams consider using their own dedicated IPs instead of shared pools. Dedicated IPs do isolate you from other senders’ reputation issues, which is an advantage. But there are important tradeoffs: warming up a dedicated IP takes significant time – much longer than most expect. You may need multiple dedicated IPs to reach necessary volume, which multiplies your infrastructure burden. You’ll need to split traffic among them while each builds reputation.
Managed infrastructure avoids these problems by giving you pre-warmed, carefully distributed infrastructure that’s already proven itself.
Our Revenue Director, Chrisley Ceme, is leading the Triggered Outbound program.Chrisley’s gone deep on this strategy and can walk you through:
- How Triggered Outbound fits with your outbound goals
- What triggers are available (and what’s possible within our platform)
- Pricing, onboarding, and getting started
