We Tested Mailerr with 30 Email Accounts: Here’s Our Review

You are here to understand Mailerr, not to read another feature list.

You want clear answers:

• How is the infrastructure structured?
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• What limits exist?
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• How are things supposed to work when many email accounts are involved?

That is what this review focuses on.

We tested Mailerr using 30 email accounts to look past the surface. Not to judge campaigns. Not to compare results.

Only to understand how Mailerr behaves when multiple inboxes exist at the same time. Things like inbox limits, domain handling, sending guidance, and overall control. 

This review shares those observations.

Before going to choose, it helps to first understand what Mailerr is built for and how it works, and whether it fits your needs or not.

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Key Takeaways

• Mailerr is used to set up domains and mailboxes. It does not send emails or run campaigns.
  
  
• When you use Mailerr, all cold email sending, follow-ups, and pacing are handled in a separate sending tool.
  
  
• Inside Mailerr, you only see inbox and domain health signals like bounces, spam reports, and blacklist checks. It does not show campaign results like opens, clicks, or replies.
  
  
• As the number of inboxes and domains grows, scaling with Mailerr becomes harder because of plan limits and extra costs.
  
  
• Mailforge is the best alternative built for scaling cold email, with automated DNS setup and $2–$3 per mailbox pricing for managing many inboxes.
  
  
• Mailerr works well for smaller setups, while Mailforge is better when cold email volume grows.

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What Is Mailerr?

Mailerr is a cold email infrastructure tool used to set up and manage email inboxes and domains for outreach.

You can create inboxes, connect or buy domains, and have important records like SPF, DKIM, DMARC, and MX configured automatically.

All inboxes and domains are managed from one place, which makes it easier to stay organized when working with multiple accounts.

After the setup is done, the inboxes can be used in your email sending tool for outreach.

Get Mailforge and scale cold email with automated DNS and hundreds of inboxes.

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How Mailerr Handles Email Infrastructure

This is how Mailerr manages domains, inboxes, and email setup in one system before outreach begins.

You add or buy domains

You add your own domains or buy new ones inside Mailerr.

Every email inbox is created under a domain, so domains stay at the center of the setup.

Mailerr sets up authentication automatically

After a domain is added, Mailerr automatically sets up SPF, DKIM, DMARC, and MX records.

This prepares the domain for email without manual DNS changes.

Inboxes are created under each domain

Mailerr allows email inboxes to be created under a domain, based on the selected plan.

All inboxes remain linked to their domain.

Sender details are managed per inbox

Each inbox has its own sender name and profile details.

This keeps email identities clear and separate.

Workspaces help keep things clean

Mailerr uses workspaces to organize inboxes and domains across different teams, clients, or campaigns.

Inboxes are ready to use with sending tools

Once inboxes are set up, they are connected to external email sending tools.

‍Mailerr stays focused on preparing the infrastructure before emails are sent.

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Mailbox Access, Administrative Control, and Structure

Here is who controls the mailboxes, how inboxes are grouped, and why this setup matters when many accounts are involved.

Mailbox access and administrative control

Mailerr gives you direct access to every email account created inside the platform.

Each inbox can be opened and managed as its own email account, just like a normal mailbox.

You can:

• Open the inbox directly
  
  
• Manage sender names and profile details
  
  
• Control basic mailbox settings
  

There is no limited or read-only view. Each mailbox stands on its own, which makes it clear who controls which inbox, especially when many accounts exist.

Workspace structure for managing multiple inboxes

Mailerr uses workspaces to organize inboxes and domains.

Each workspace holds its own set of inboxes, so accounts stay separated instead of sitting in one long list.

This means:

• Inboxes for different teams or clients stay grouped
  
  
• Domains and inboxes do not get mixed together
  
  
• It is easier to see where each inbox belongs
  

How Domain and Sender Authentication Work in Mailerr

This section explains how Mailerr gets domains and sender details ready for email use.

Domain authentication setup

When a domain is added to Mailerr, it is made ready for sending emails.

Mailerr sets up the needed DNS records for the domain.

These include:

• SPF
  
  
• DKIM
  
  
• DMARC
  
  
• MX
  

Mailerr does this automatically. You do not need to touch DNS settings yourself.

This makes things easier, especially when you are using more than one domain.

Sender identity handling

Each email inbox has its own sender details. This includes the sender's name and profile information.

These sender details stay linked to the inbox, which helps keep each email account clearly identified when many inboxes exist at the same time.

In simple terms, Mailerr prepares domains and sender identity so inboxes are ready without manual setup.

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How Mailerr approaches deliverability and monitoring

Mailerr treats deliverability as part of the infrastructure, not as a campaign feature.

Once domains and inboxes are set up, Mailerr monitors a few deliverability signals that directly affect whether emails continue to be sent properly.

These are not engagement metrics. They are basic health checks.

Mailerr monitors:

• Blacklisting issues
  
  
• Spam reports
  
  
• Bounced emails
  

These signals help indicate when an inbox or domain may be running into trouble and needs attention.

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Sending recommendations per inbox

Mailerr does not enforce hard daily sending limits on inboxes.

Instead, it provides a clear recommendation.

• Suggested volume is 30 to 50 emails per inbox per day
  
  
• This recommendation is shared to help protect sender's reputation
  
  
• Mailer clearly states that sending more than this can hurt deliverability
  

This guidance is applied per inbox, not across all inboxes together.

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Why do these safeguards exist in cold email infrastructure

Cold email setups often use many inboxes at the same time.

When inbox health is ignored or sending volume goes too high, problems can spread quickly across accounts.

Monitoring basic health signals and sharing clear per-inbox sending guidance helps:

• Reduce sudden deliverability issues
  
  
• Avoid inbox or domain damage
  
  
• Keep email accounts usable over time
  

In short, Mailerr focuses on basic inbox health checks and clear sending guidance to help keep cold email setups stable.

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What Visibility Mailerr Provides After Sending

What Visibility Mailerr Provides After Sending

After emails start sending, Mailerr keeps visibility focused only on email setup health.

What you can see:

• inbox and domain health signals
  
  
• blacklisting issues
  
  
• spam reports
  
  
• bounced emails
  

These signals help you understand whether your inboxes and domains are staying healthy or starting to face problems.

What you cannot see:

• opens
  
  
• clicks
  
  
• replies
  
  
• campaign or sequence performance
  

By keeping visibility limited to the inbox and domain health, Mailerr avoids mixing setup issues with campaign results.

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Mailerr Pricing 

Mailerr prices plans based on how many inboxes and domains you want to manage.

You can pay monthly or save 5% with annual billing.

Solopreneur - $40/month

This works for small setups. You can run up to 10 inboxes across 3 domains, with domains billed at $16 per year.

Business - $100/month

This is for growing teams. You get up to 30 inboxes and 10 domains, domains cost $15 per year, and you can add more inboxes for $4 per month.

Enterprise - $360/month

This plan fits larger teams. It supports up to 100 inboxes and 35 domains, domains cost $14 per year, and extra inboxes cost $3.50 per month.

As your inbox and domain count grows, the plan and add-on costs scale with it.

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Limitations of Mailerr for Cold Email Use Cases

Once cold email moves beyond small setups, these are the limits teams often notice with Mailerr.

• Cold email needs to scale fast, but Mailerr’s setup adds limits as volume grows. Inbox and domain counts are tied to plans, which can slow down scaling when outreach increases.
  
  
• Mailerr focuses only on email setup, not sending. To scale cold email, you must always rely on another tool for sequences, follow-ups, pacing, and daily volume control.
  
  
• There are no enforced sending limits per inbox. Mailerr recommends 30–50 emails per inbox per day, but it does not block higher sending. At scale, this puts all safety responsibility on the user.
  
  
• Deliverability visibility is limited for high-volume cold email. You can see blacklisting issues, spam reports, and bounces, but there is no inbox placement view or deeper insight when large volumes underperform.
  
  
• Cold email performance data is not visible inside Mailerr. Opens, clicks, and replies must be checked in another tool, which adds friction as inbox and campaign count increase.
  
  
• Scaling also increases cost complexity. Extra inboxes and domains come with added fees, and domains are billed yearly outside the main plan price.

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When Teams Look for an Outbound-Focused Alternative

This is usually the point where poeple rethink their setup.

As cold email grows, teams often want fewer limits, less manual control, and infrastructure that scales more smoothly.

When inbox count, domain count, and sending volume increase, managing plans, add-ons, and multiple tools can start to feel heavy.

At this stage, teams often look for an option that:

• Built with scaling outbound in mind
  
  
• Reduces reliance on multiple tools
  
  
• Offers more control around sending and growth
  

At this stage, teams often consider tools built specifically for scalable cold email infrastructure, such as Mailforge.

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Mailforge: Best Outbound-Focused Mailerr Alternative

Mailforge is built specifically for scalable cold email outreach.

While some tools focus mainly on setup, Mailforge is designed to support teams that want to move fast, scale freely, and run cold outreach at volume without adding complexity at every step.

Mailforge provides a distributed email infrastructure with shared IPs, similar to Gmail or Outlook, but it is built for cold outreach from day one. 

Domains and mailboxes can be set up in minutes, and all technical records like SPF, DKIM, DMARC, and custom tracking are handled automatically.

Mailforge is built to let teams:

• Create hundreds of domains and mailboxes quickly
  
  
• Add unlimited mailboxes at a low per-mailbox cost
  
  
• Work across multiple workspaces without friction
  

This makes it easier to grow cold email volume without constantly worrying about plan limits slowing things down.

Mailforge also works with any sending software, including Salesforge, and supports multi-channel outreach when used with Salesforge, combining email and LinkedIn in one flow.

From a cost perspective, Mailforge keeps pricing simple.

Mailboxes are priced at $3 to $2 per mailbox per month, which makes scaling inbox count more predictable as outreach grows.

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Conclusion

Mailerr works well when the goal is to set up domains and mailboxes quickly and keep the technical side simple.

It handles domain setup, authentication, and inbox creation in a clean and structured way.

As cold email grows, the needs often change. Scaling outreach usually means managing more inboxes, more domains, and higher sending volume.

At that stage, limits around plans, add-on costs, and the need for multiple tools become more noticeable.

In those cases, teams sometimes also look at options like Mailforge, which is built around distributed infrastructure and higher inbox counts.

It approaches cold email with scaling in mind, keeps setup automated, and works alongside different sending tools. 

That makes it relevant where scale and simplicity matter more than just initial setup.

Try Mailforge! Create and manage hundreds of inboxes with automated DNS, at just $2–$3 per mailbox per month.

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