5 Best Email Infrastructure Tools for Agencies
Managing cold email campaigns at scale is tough - spam filters, deliverability issues, and domain reputation can make or break your results. The right email infrastructure tools solve these problems by automating setup, improving sender reputation, and ensuring compliance with email standards like SPF, DKIM, and DMARC.
Here are the top 5 email infrastructure tools for agencies in 2025:
- Infraforge: Offers dedicated IPs, real-time monitoring, and automated domain setups. Best for agencies needing full control over deliverability. Starts at $17/month per slot.
- Inframail: Unlimited inbox creation with flat-rate pricing. Ideal for scaling campaigns. Starts at $99/month.
- Mission Inbox: Designed for high-volume campaigns with features like automated warm-ups and real-time monitoring. Starts at $150/month.
- Mailscale: Affordable and scalable, with built-in deliverability tools and warm-up automation. Plans start at $79/month.
- Maildoso: Focuses on speed, automating domain and inbox setups in minutes. Quarterly plans start at $99.
Quick Comparison
| Tool | Starting Price | Key Features | Best For |
|---|---|---|---|
| Infraforge | $17/month per slot | Dedicated IPs, real-time monitoring | Full deliverability control |
| Inframail | $99/month | Unlimited inboxes, flat-rate pricing | Scaling campaigns |
| Mission Inbox | $150/month | High-volume support, warm-up tools | Large-scale outreach |
| Mailscale | $79/month | Affordable, scalable, warm-up tools | Budget-friendly scalability |
| Maildoso | $99/quarter | Fast setup, AI-powered warm-ups | Quick deployment |
Each tool automates key email authentication protocols and addresses deliverability challenges. Choose based on your agency’s size, budget, and campaign needs.
1. Infraforge
Infraforge is tailored specifically for agencies that need to manage large-scale cold email campaigns. Unlike general email services like Google Workspace or Microsoft 365, Infraforge zeroes in on the unique challenges of cold email delivery, offering tools and features designed to keep emails flowing smoothly and landing where they should - right in the inbox.
The platform solves a common pain point for agencies: maintaining high deliverability rates while managing the heavy email volumes that come with multi-client campaigns. Traditional email providers often fall short when it comes to handling this kind of workload.
Deliverability Optimization
Deliverability is at the heart of Infraforge’s design. To protect your sender reputation, the platform assigns dedicated IPs to each mailbox, ensuring your performance isn’t affected by other users. Features like sender rotation and sending limits help distribute email volume, minimizing the risk of being flagged as spam.
Real-time monitoring keeps an eye on delivery rates, instantly alerting you to any issues. And with pre-warmed resources, you can skip the usual delays associated with new campaigns, getting up and running faster while safeguarding your deliverability.
"Infraforge quickly helped to solve a challenge regarding email deliverability. What I like about Infraforge is its ease of use and quality of support."
– Silver L, CEO
Scalability Features
Scaling is seamless with Infraforge. The platform supports unlimited domains, mailboxes, and workspaces, making it easy to organize campaigns for multiple clients.
As your email volume grows - say, beyond 100,000 messages per month - Infraforge lets you add dedicated IPs to handle the increased load. The platform's API also automates the creation of domains and mailboxes, removing manual tasks and speeding up campaign setups.
"Advanced Private Email Infrastructure That Makes Scaling Easy. Scale your cold outreach without getting flagged as spam. Create thousands of domains and mailboxes with a dedicated IP and automated DNS set-up."
– Infraforge
Authentication Protocols
Infraforge simplifies email authentication by automatically configuring DKIM, SPF, and DMARC protocols for each domain in just a few minutes. These settings follow industry best practices, reducing the chance of misconfigurations that could hurt your deliverability.
Why does this matter? Emails with DKIM signatures are 30% less likely to be altered during transmission, and organizations using DMARC report 90% fewer successful phishing attempts.
Pricing Models
Infraforge uses a flexible mailbox slot system, starting at $17 per month (billed annually) with a minimum of 10 slots. You pay for total capacity rather than active mailboxes, allowing you to activate or deactivate slots as needed.
For larger operations, 200 mailboxes cost $651 per month - offering significant savings compared to competitors. Additional services include dedicated IPs for $99 per month, SSL and domain masking for $2 per domain monthly, and a centralized email view ("Masterbox") for $7 per workspace monthly. Domains are priced at $13 annually, and personalized consulting sessions are available for $500 each.
"During my time at a Fortune 500 company and now across all our products, Infraforge has been my go-to solution for Email Infrastructure. Its deliverability and impact are unmatched. If you're serious about outreach and want the best tool in the market, Infraforge is the only choice."
– Rahul Lakhaney, Former VP, Gartner; now CEO @ Enrich.so and Maximise
Up next, we’ll dive into Inframail, another powerful solution for agencies.
2. Inframail
Inframail is Infraforge's specialized Microsoft-based solution, tailored for agencies running large-scale cold email campaigns. It tackles one of the biggest headaches agencies face: the tedious process of setting up domains and email accounts. With its flat-rate, unlimited approach, agencies can create as many email accounts as their plan allows, simplifying operations and saving time.
Deliverability Optimization
Inframail boasts deliverability rates of over 98%, thanks to Microsoft's reliable infrastructure and dedicated email servers for each user. It also features a real-time monitoring tool that provides full campaign visibility and automates email setup - claiming to be 50 times faster than manual methods.
"Inframail is one of my favorite SaaS tools for improving email infrastructure. It saves me tons of time setting up domains and their records. The boring manual work was so frustrating. What used to stop me from doing real volume with my outreach has become a piece of cake." – Jovan, 9-figure CRO
Scalability Features
Designed with scalability in mind, Inframail is perfect for agencies managing multiple clients. The Agency Pack supports up to 15 domains per day, while the Unlimited Plan handles 5 domains daily. It also integrates seamlessly with popular email tools like Instantly.ai, Smartlead, and Reachinbox, ensuring a smooth workflow from setup to execution.
"A no-brainer if you're doing email outreach at scale. It completely takes the headache out of account setups and has already saved me hundreds in account costs after using it for just two months. The support is responsive and fast and excited to see the product continue to get better!" – Lewis Clark, lead gen agency
Authentication Protocols
To ensure emails are properly authenticated, Inframail automatically configures SPF, DKIM, and DMARC records. This takes the guesswork out of email authentication, reducing the risk of errors that could cause messages to be flagged as spam or suspicious.
Pricing Models
Inframail offers two straightforward pricing options for agencies of different sizes:
- Unlimited Plan: $99 per month, includes one dedicated IP and allows setup for 5 domains daily.
- Agency Pack: $249 per month, includes three dedicated IPs and supports up to 15 domains daily.
With a user rating of 4.8 out of 5, many users highlight the cost savings compared to traditional Google Workspace setups and the time saved on B2B lead generation campaigns. By eliminating the per-mailbox cost, Inframail makes budgeting for large-scale campaigns much easier.
Up next, we’ll dive into another noteworthy solution.
3. Mission Inbox
Mission Inbox stands out as a specialized platform tailored for high-volume sales teams focused on cold email outreach. Unlike traditional email services that often impose restrictions or risk account suspension for cold emailing, Mission Inbox is designed to support large-scale campaigns with ease.
Deliverability Optimization
At its core, Mission Inbox prioritizes email deliverability. The platform incorporates built-in checks, automated warm-ups, and proprietary tools like Pre-send Shield™ and the OBM Engine to ensure emails land in inboxes rather than spam folders.
The results speak for themselves. Users have reported 20% higher open rates and an 80% increase in reply rates after switching to Mission Inbox. These improvements translate directly into more qualified leads and better ROI for agencies running cold email campaigns.
"Running a cold email agency isn't easy, especially handling the deliverability component that not many people have expertise in. You guys allowed me to effortlessly scale the volume I had in the past and even have crazy high open rates, bringing my clients more interested replies per campaign." – Bobby Offterdinger, CEO at TAM to Target
What sets Mission Inbox apart is its transparent infrastructure. Agencies retain full control over their email accounts, data, and records, avoiding the limitations imposed by third-party providers. This level of control creates a solid foundation for scalable and reliable email outreach.
Scalability Features
Mission Inbox is built to handle enterprise-level email volumes, making it a go-to choice for agencies of all sizes. The platform supports campaigns ranging from 10,000 to 30 million emails per month. Its centralized dashboard allows real-time monitoring of IPs, domains, and mailboxes, simplifying the management of multiple client campaigns.
A great example of its scalability comes from Gobvio, an agency managing 450,000 emails per month with Mission Inbox. The platform streamlined their operations and improved their campaign performance.
"Our agency sends roughly 450,000 emails/mo. Having that volume with Gmail, Outlook, and other infrastructures was a headache. Mission Inbox made it super easy to manage everything in a single place while having even better open and reply rates." – Velimir Elezovic, Head of Sales at Gobvio
Authentication Protocols
Mission Inbox simplifies email authentication by automatically configuring SPF, DKIM, and DMARC records. Its standout feature is the auto-push DNS integration with popular services like Cloudflare and GoDaddy, making it easier for agencies to manage multiple domains for different clients.
Pricing Models
Mission Inbox offers flexible pricing options to suit a variety of needs. Plans start at $150 per month, which includes 30 inboxes and 10,000 email sends. Agencies can add more inboxes and increase volume as needed, ensuring costs scale with client demands.
For larger operations, custom pricing is available based on email volume and team size. There's also a subscription tier starting at $250 per month, which includes 2 mailboxes, with additional mailboxes priced at $3 each per month. This pricing structure makes it accessible for smaller agencies while remaining cost-effective for high-volume campaigns.
Additionally, Mission Inbox provides full API access, allowing developers to integrate its deliverability tools into their own systems. This feature is particularly useful for SaaS companies and agencies with unique technical requirements.
4. Mailscale
Mailscale tackles the usual cold email challenges by automating processes and keeping costs low. It simplifies cold email infrastructure, cutting down on manual tasks and expenses, which makes scaling up much quicker.
Deliverability Optimization
One of Mailscale's standout features is how it handles deliverability. It automates the setup of DNS records for DKIM, DMARC, and SPF, taking the technical headache off agency teams. Plus, it includes a built-in warm-up process to help new email accounts establish a strong sender reputation before campaigns go live. The platform promises an impressive 95–100% deliverability rate for professional inboxes like Google and Outlook. If deliverability drops, Mailscale pledges to recover the domains within seven days or provide refunds or replacement domains.
This isn't just talk - there's proof to back it up. In April 2025, a user shared their experience setting up 200 domains and inboxes. They described the process as "seamless, fast, and cost-effective", which gave them the confidence to launch their campaign while saving valuable time. Such reliable deliverability makes scaling campaigns a much smoother process.
Scalability Features
Once deliverability is taken care of, Mailscale makes scaling campaigns simple. It’s built to handle large-scale cold email operations, supporting up to 1,000 email accounts. It also integrates with popular cold email tools like Saleshandy, Instantly, Smartlead, and ReachInbox, making it easy to streamline workflows. On top of that, Mailscale automates account setup at a speed 50 times faster than manual methods, and it costs about one-fifth of what traditional providers charge. For agencies with growing needs, the Enterprise plan even lets you add extra email inboxes for just $1 per month each.
Pricing Models
Mailscale’s pricing structure is designed to suit agencies of various sizes. There are three main plans:
- Solopreneur Plan: $79 per month for up to 15 email accounts
- Business Plan: $119 per month for up to 50 email accounts
- Enterprise Plan: $249 per month for up to 200 email accounts
Breaking it down further, the average cost per account is about $5.26 for the Solopreneur Plan, $2.38 for the Business Plan, and $1.20 for the Enterprise Plan. This makes Mailscale a much more affordable choice compared to traditional solutions, especially for agencies managing multiple accounts.
Mailscale has a 4.5-star rating based on 52 reviews. Users often highlight its ease of use and time-saving features, though some have mentioned occasional technical hiccups and inconsistent deliverability.
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5. Maildoso
Maildoso is all about speed and automation, making it a go-to choice for agencies that need to manage large-scale email outreach. The platform promises to set up hundreds of accounts and domains in just minutes, saving valuable time.
Scalability Features
Maildoso can register up to 250 domains and create 1,000 mailboxes in just 10 minutes. This level of efficiency eliminates the usual delays agencies face when scaling their email operations.
The platform takes care of the entire technical setup automatically, from creating domains and email accounts to configuring the necessary backend settings. With its shared IP address system, Maildoso helps smaller agencies build a positive reputation with email providers, even if they lack the resources to manage dedicated IP warm-ups.
To minimize spam flags, the platform automates domain rotation and provides a centralized dashboard. This dashboard simplifies email management by allowing users to send and receive emails from one master account. Additionally, Maildoso integrates seamlessly with popular cold email tools like Saleshandy and Woodpecker, making it easy to incorporate into existing workflows.
Deliverability Optimization
Maildoso doesn't just focus on setup speed - it also prioritizes email deliverability. The platform uses IP rotation and an AI-powered warm-up feature to improve sender reputation and keep emails out of spam folders. The AI warm-up even performs in-browser actions to further enhance reputation.
"If you're not sending images or links, your deliverability rate can hit 95%!"
To help agencies track their campaigns, Maildoso provides automatic daily inbox placement tests, offering real-time insights into where emails are landing. The platform also includes a master inbox feature, which makes managing replies across multiple accounts much easier.
Users have praised Maildoso’s deliverability tools. Kshitij D. shared, "Maildoso helps us set up warm mailboxes quickly without needing separate GSuite accounts. It saves us time, reduces setup friction, and keeps our cold outreach deliverability high". Similarly, Kavya R. said, "Maildoso helps automate cold email outreach while maintaining high deliverability. It solves the problem of emails landing in spam by using inbox rotation and warm-up features".
Authentication Protocols
Maildoso simplifies email authentication by automatically configuring SPF, DKIM, DMARC, and MX records. This hands-free approach ensures compliance with industry standards while protecting sender reputation.
The platform also uses its own SMTP servers and only allows emails to be sent from verified domains. This added layer of security ensures agencies can focus on their campaigns without worrying about the technical complexities of email authentication.
Pricing Models
Maildoso offers flexible quarterly plans to suit agencies of all sizes:
- Small Package: $99 every 3 months (12 email accounts, 3 free domains)
- Starter Package: $299 every 3 months (40 email accounts, 10 free domains)
- Growth Package: $999 every 3 months (140 email accounts, 35 free domains)
- Pro Package: $2,199 every 3 months (400 email accounts, 100 free domains)
For those managing fewer accounts, individual mailboxes are priced at $1.40 per month with an annual plan or $1.80 per month with a quarterly plan. With this pricing structure, Maildoso caters to both small teams and large-scale operations handling hundreds of accounts.
Comparison: Pros and Cons
When choosing the right tool for your agency's needs, it's important to weigh each platform's strengths and limitations. Here's how they stack up:
Infraforge offers a standout feature with dedicated IP addresses for each mailbox and automated DNS configuration, giving agencies full control over email deliverability. This level of control is reflected in its perfect 5/5 G2 rating. However, the service comes with higher upfront costs, as mailbox slots start at $17/month on an annual plan (with a minimum of 10 slots required).
Inframail shines with its unlimited inbox model, making it a cost-effective choice for agencies managing multiple campaigns. Its $99/month Unlimited Plan, which includes one dedicated IP, eliminates per-mailbox restrictions, allowing for seamless scaling. That said, smaller operations may find the upfront investment challenging.
Mission Inbox prioritizes simplicity and speed, although its limited public metrics make it harder to fully evaluate its performance.
Mailscale is built for scalability, featuring automated technical setup and integrated email warm-up tools. Pricing starts at $79/month for up to 15 accounts, while the Enterprise Plan, at $249/month, reduces the cost per mailbox to as low as $1.20 for up to 200 accounts. While this pricing structure is attractive for larger agencies, smaller teams may find the initial costs steep.
Maildoso impresses with its quick setup process and responsive customer support, earning a strong 4.8/5 G2 rating. Its quarterly pricing, starting at $99 every three months for the Small Package, provides an affordable entry point. However, the platform's lack of extensive customization options and absence of monthly payment plans could pose challenges, especially for agencies with tighter cash flow.
Here's a quick comparison of the key points:
| Tool | G2 Rating | Starting Price | Key Strength | Main Limitation |
|---|---|---|---|---|
| Infraforge | 5/5 | $17/month per slot | Full deliverability control | Higher initial cost |
| Inframail | N/A | $99/month (Unlimited Plan) | Unlimited inboxes | Larger initial investment |
| Mission Inbox | N/A | Not specified | Simplicity and speed | Limited transparency |
| Mailscale | 5/5 | From $79/month (15 accounts); Enterprise: $249/month (200 accounts) | High scalability | Higher initial costs |
| Maildoso | 4.8/5 | $99/3 months | Rapid setup and support | Limited customization; no monthly payments |
Each platform also automates key email authentication protocols, which is critical for both deliverability and security. With phishing responsible for 85% of cyberattacks in 2022, proper email authentication is no longer optional - it's essential.
Cost efficiency largely depends on your agency's size and usage. For instance, Mailscale’s Enterprise Plan offers the lowest per-mailbox cost at $1.20, while Infraforge provides unmatched control at approximately $2.50–$4.00 per mailbox monthly. For smaller agencies managing fewer than 50 accounts, Maildoso’s quarterly packages strike a solid balance between affordability and features.
"All of these requirements have been well-documented best practices for years. A lot of senders have already implemented them. Authenticating your email traffic should be something that you're already doing if you care about the health of your email traffic as well as your infrastructure."
- Marcel Becker, Senior Director of Product at Yahoo
Ultimately, the best platform depends on your agency's specific needs: Infraforge for control, Inframail for unlimited scaling, Maildoso for speed, and Mailscale for cost-effective volume. Whether you're a boutique agency or managing hundreds of client campaigns, there's a solution tailored to your operational goals.
Which Tool Should You Choose?
When it comes to email infrastructure, selecting the right tool can make or break your deliverability and scalability efforts. The best choice will depend on your agency's size, budget, and specific needs.
If deliverability control is your top priority, Infraforge is a strong contender. It offers dedicated IP addresses for each mailbox and automated DNS configuration, giving you greater control over email reputation. At $17/month per slot (with a minimum of 10 slots), Infraforge is perfect for agencies that need to maintain tight control over deliverability metrics.
Agencies managing 50 or more campaigns might find Inframail's Unlimited Plan to be the most cost-effective option. For $99/month (billed annually), this plan eliminates the per-mailbox pricing model, making it easier to scale without unpredictable costs. It’s a great fit for campaigns sending thousands of emails daily.
Smaller agencies with fewer than 20 accounts should consider Maildoso. Starting at $99/month (billed quarterly), it offers a budget-friendly entry point while delivering reliable performance. However, the quarterly billing model requires some foresight in planning cash flow.
For agencies experiencing rapid growth, Mailscale's Enterprise Plan is designed for high-volume needs. At $199/month for up to 200 accounts, the per-mailbox cost averages around $1.00. This makes it ideal for those managing large-scale outreach campaigns or onboarding new clients quickly.
If speed and simplicity are critical, Mission Inbox is your go-to option. It emphasizes rapid deployment, making it perfect for agencies that need to get up and running without delays.
It’s also worth considering how each tool integrates with your existing workflow. For example, Mailscale offers native integrations with popular cold email tools, which can streamline your processes and save time.
Ultimately, your choice boils down to balancing factors like control, scalability, and cost. Agencies handling sensitive client campaigns may lean toward Infraforge for its robust deliverability features, while those focused on scaling quickly might prefer Inframail or Mailscale for their cost-effective, high-volume plans.
No matter which platform you choose, all of these tools support essential email standards like DKIM, SPF, and DMARC. The key is to align your selection with your agency’s current needs and future growth goals.
FAQs
What should agencies look for when choosing the right email infrastructure tool?
When choosing an email infrastructure tool, agencies need to prioritize a few critical factors to ensure it aligns with their requirements. First and foremost, deliverability is key - the tool should consistently get emails into recipients' inboxes rather than being flagged as spam. Equally important is scalability, allowing the tool to handle growth effortlessly without introducing unnecessary complexity or skyrocketing costs.
It's also essential to find a solution that offers smooth integration with existing systems like CRMs, alongside robust analytics for monitoring and improving performance. Support for email authentication protocols such as DKIM, SPF, and DMARC is non-negotiable to maintain security and credibility. Finally, take a close look at pricing transparency and assess whether the tool delivers solid value for the features it provides.
How do email authentication protocols like DKIM, SPF, and DMARC help agencies improve deliverability and security?
Email authentication protocols like DKIM, SPF, and DMARC are essential for improving email deliverability and security, especially for agencies. These tools work together to confirm that emails come from legitimate sources, helping to guard against spoofing and phishing attacks.
- DKIM: This protocol attaches a digital signature to emails, verifying that the content remains unchanged during transit.
- SPF: It identifies which mail servers are permitted to send emails on behalf of a specific domain.
- DMARC: Building on DKIM and SPF, this protocol lets domain owners decide how to handle emails that fail authentication - whether to reject them, flag them, or take another action.
Using these protocols not only strengthens email security but also helps agencies maintain a good sender reputation. This reduces the chances of emails landing in spam folders and ensures messages consistently reach recipients' inboxes.
What are the advantages of using a dedicated IP address for email campaigns, and how does it impact deliverability?
Using a dedicated IP address for email campaigns comes with some clear advantages, particularly when it comes to ensuring your emails actually reach inboxes. Unlike shared IPs, where your email reputation can be impacted by the actions of others, a dedicated IP gives you full control over your sending reputation. In this setup, email providers judge your IP based solely on your own sending habits, which significantly improves the chances of your emails avoiding the spam folder.
A dedicated IP also simplifies the process of setting up email authentication protocols like SPF and DKIM, which help confirm the authenticity of your emails and further boost deliverability. Plus, troubleshooting becomes much easier - any issues with performance are directly tied to your own practices, not someone else’s. For agencies or businesses managing large-scale email campaigns, having a dedicated IP is a must for dependable and consistent communication.