How to Choose the Best Email Marketing Software (with a free checklist and mistakes to avoid)

Choosing email marketing software is no easy feat. With every platform promising the same results—better engagement, more conversions, smoother workflows—it’s easy to hit decision fatigue before you’ve even made a shortlist.

Yet, with email marketing delivering an average ROI of $36 for every $1 spent, your choice of software can make that goal easier (or more difficult) to achieve.

The best email marketing platforms for agencies reduce administrative and reporting chaos, support multiple clients and workspaces, offer advanced customer journeys, and feature smart automation that makes personalization across campaigns easy. 

In this guide, we’ll walk you through:

• The key features that matter if you offer email marketing services 
• A checklist to help you evaluate and choose the right platform
• 🎁 Bonus: 10 common mistakes to avoid
  
  

TL;DR:  How to choose email marketing software?

1. Start with your goals: Define what success looks like for your agency and clients.
   
2. Map must-have features: Focus on deliverability, collaboration features, automation, personalization, and integrations.
   
3. Shortlist smartly: Compare 3-5 tools that align with your workflows and budget.
   
4. Test in real life: Run free trials using real campaigns and data before you migrate.
   
5. Avoid the most common pitfalls: Overpaying for unused features or skipping deliverability checks are the biggest mistakes.

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What you need to know before you start comparing
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Types of email marketing software

Depending on an agency’s service model, client profile, and approach, there are two main ways to use email marketing software: 

• Use one platform for all clients, or
• Choose different software based on each client’s industry and vertical, or their budget.

Either way, understanding the four main types will help you filter options more quickly and choose what best fits your team and clients.

1. Newsletter tools

Newsletter tools are built for sending bulk email campaigns, like updates to subscribers, product announcements, or blog roundups. 

Examples: MailerLite, Substack, EmailOctopus

Best used for: Clients focused on brand awareness or content distribution. These tools make it easy to design and schedule regular newsletters across multiple client accounts without deep automation setups. They’re especially good for creators, publishers, or lifestyle brands that want to stay visible and nurture relationships over time.

Not ideal for: Clients who need advanced targeting or data-driven automations. If your agency manages nurture sequences or personalized campaigns, you’ll quickly outgrow newsletter-only platforms.

2. Marketing automation tools

Marketing automation platforms go beyond sending newsletters—they help you design behavior-based campaigns that trigger automatically when a subscriber takes an action; for example, sending a welcome email after sign-up or re-engagement emails when users go inactive.

Examples: ActiveCampaign, Klaviyo, Kit

Best used for: Clients who need end-to-end customer journeys, like for SaaS onboarding flows, eCommerce re-engagement, or B2B lead nurturing.

Not ideal for: Clients who only send occasional campaigns. These tools can be expensive and harder to manage if your agency mainly handles simpler newsletters.

3. Cold outreach tools 

Cold outreach tools are designed to send personalized emails to new leads who haven’t interacted with your brand yet. They prioritize deliverability for high-volume sending and often include features like email warm-up and domain rotation.

Examples: Instantly, Apollo, Lemlist

Best used for: Agencies running outbound campaigns for clients in B2B, SaaS, or professional services. They’re great for managing cold email sequences, tracking replies, and automatically pausing sends once a lead responds.

Not ideal for: Nurturing existing subscribers or managing large marketing lists. They aren’t designed for newsletters and automation workflows.

💡 Tip: Some agencies use these alongside marketing automation tools—one for prospecting, one for nurturing.

4. All-in-one suites

All-in-one marketing suites combine email marketing, automation, CRM, and analytics in a single platform. 

Examples: HubSpot, Brevo, Zoho Marketing Plus

Best used for: Clients who need a centralized system for both marketing and sales. They let you manage multiple campaigns, track ROI across channels, and scale operations as their customer base grows. E-commerce brands managing omnichannel campaigns from a single dashboard tend to gravitate toward options like this.

Not ideal for: Smaller teams that only need email campaigns or simple automations. These platforms can be costly and complex, with more features than many businesses actually use.

💡 Tip: Some platforms offer client workspaces or sub-accounts, making it easier for agencies to manage multiple clients under one system.

Core features every email marketing software should have

Before comparing platforms, it helps to know what every modern email marketing tool should already include. These are the table stakes—the basic features you should expect, no matter the price or brand:

1. Drag-and-drop email builder: Easily design emails without coding.
   
2. Mobile-responsive templates: Make sure every email looks good on any device.
   
3. Audience segmentation: Group subscribers by behavior, interests, or demographics.
   
4. Basic automation: Set up simple workflows like welcome emails or follow-ups.
   
5. A/B testing: Test subject lines, content, or send times to improve results.
   
6. Analytics dashboard: Track open rates, click rates, and unsubscribes.

Don’t get distracted by fancy marketing terms. Most “AI-powered” or “smart” features are just core features every tool already has. What really matters are the differentiators, which we’ll go over next. 👇
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What to look out for in email marketing software: 8 features

Once you've confirmed a platform covers the basics, the following factors will determine whether it's truly a good fit.

1. Deliverability and reputation

Deliverability—your ability to consistently land in the inbox rather than spam folders—matters more than any other feature. A beautifully designed email with perfect copy is worthless if Gmail or Outlook filters it out before anyone sees it.

Look for:

• Email authentication built-in: Support for SPF, DKIM, and DMARC should come standard.
  
• Inbox placement testing: Check where your emails actually land before you hit send.
  
• Reputation monitoring: Tools to track spam complaints, bounce rates, and engagement.
  
• Dedicated IP options: Useful for high-volume senders or agencies managing multiple brands.
  
• Transparent reporting: Look beyond open rates—delivery and inbox placement data matter more.
  

🔍 Did you know? In 2024, Gmail and Yahoo introduced stricter authentication requirements that penalize bulk senders who don’t meet compliance standards—meaning even legitimate, well-written campaigns can end up in spam if your provider doesn’t maintain strong deliverability infrastructure.

2. Automation and workflow intelligence

Basic automation can send a welcome email when someone subscribes. Advanced automation goes much further. 

It can create multi-branch journeys that adjust what each subscriber sees based on their actions, purchase history, or level of engagement.

Look for:

• Visual workflow builder: Map and edit complex customer journeys without coding.
  
• Behavior-based triggers: Automate messages when someone clicks, buys, or abandons a cart.
  
• Multi-channel workflows: Coordinate emails, SMS, and even retargeting ads in one flow.
  
• Conditional logic: Adjust timing and content based on user actions or inactivity.
  
• Reusable templates: Clone or repurpose high-performing automations easily.

✅ When testing new platforms, try recreating one of your clients’ onboarding or cart recovery workflows. The right tool should make this setup quick and painless—that’s how you’ll know it’s easy to scale.

3. Personalization and AI capabilities

According to Campaign Monitor, personalized subject lines can lift open rates by 26%. 

Thankfully, personalization now goes far beyond adding someone’s first name to an email. Modern platforms use AI to tailor messages, timing, and offers to each subscriber automatically.

Look for:

• Smart send-time optimization: Finds the best moment to reach each contact based on past behavior.
  
• AI-assisted copywriting: Suggests subject lines, CTAs, and content variations.
  
• Product recommendations: Uses browsing and purchase history to feature relevant items.
  
• Dynamic content blocks: Automatically swap visuals or messages based on customer segments.

💡 Tip: AI can save your team hours, but it still needs a human touch. Always review AI-generated content and make the final call to ensure the tone and message stay on-brand.

🔗 Is your agency exploring ways to use AI beyond email marketing? Check out our guide to the best AI tools for marketing agencies.

4. Integrations and API access

Native integrations typically work more reliably than third-party connectors built through platforms like Zapier. 

Check whether your essential tools have direct integrations and whether the email marketing platform offers robust API access in case you need custom integrations later.

Common integration categories include:

• CRM systems: Salesforce, HubSpot, Pipedrive.
• E-commerce platforms: Shopify, WooCommerce, BigCommerce.
• Analytics tools: Google Analytics, Mixpanel, Segment.
• Advertising platforms: Facebook Ads, Google Ads, TikTok.
• Payment processors: Stripe, PayPal, Square.

5. Analytics and reporting

Basic metrics, like open rates, click rates, and unsubscribe rates, tell you what happened.

Advanced analytics tell you the why and help you predict what's next.

Look for:

• Cohort analysis: Track how subscriber groups behave over time.
  
• Revenue attribution: Connect email campaigns directly to sales and ROI.
  
• Predictive segmentation: Identify which subscribers are most likely to buy or churn.
  
• Custom reports: Easily export or visualize data without needing a data science degree.
  

Key metrics to track beyond the basics:

• Deliverability rate: Percentage of emails that actually reach the inbox.
  
• Conversion rate: Percentage of recipients who complete your desired action.
  
• Subscriber retention: How long people stay engaged on your list.
  
• ROI per campaign: Revenue generated divided by total campaign costs.

💡 Tip: When evaluating tools, test how quickly your team can answer questions like: “Which client segment drives the most revenue?” or “How does engagement change over a subscriber’s first 90 days?” If finding those answers takes too many clicks or exports, your reporting system may slow you down in the long run.

6. Security, compliance, and privacy infrastructure

Platforms handling customer data carry significant responsibility. Think about it: a single data breach or privacy violation can harm your client’s reputation and hurt deliverability.

Look for:

• SOC 2 compliance: Ensures the platform follows strict data security standards.
  
• End-to-end encryption: Keeps customer data protected in transit and at rest.
  
• GDPR-ready features: Consent tracking, preference centers, and automated unsubscribe tools.
  
• Regional data storage: For agencies with global clients, choose vendors that store data locally (e.g., EU servers for European customers).

Note: Email providers like Gmail and Outlook constantly track how people interact with your messages (opens, clicks, spam complaints). If a platform doesn’t manage consent properly or gets flagged for spam, its users’ deliverability is likely to drop.

7. Roadmap and vendor stability

You're not just buying software—you're committing to a long-term partnership. The platform you choose today will house your subscriber data, campaign history, and automation workflows for years. 

So you need confidence that the provider will continue to evolve.

Look for:

• Regular product updates: Frequent releases signal an active, well-supported platform.
  
• Public product roadmap: Transparency about what’s coming next shows commitment to improvement.
  
• Responsive support and community feedback: Check how quickly the company addresses user requests or bugs.
  
• Stable ownership: Established or well-funded companies are less likely to be acquired or shut down suddenly.

🔍 Did you know? Apple’s iOS 18.1 now automatically summarizes long emails. That means clarity and strong subject lines matter more than ever. As inboxes get smarter with AI, choose a platform that not only has a solid track record but also adapts quickly to new email technologies and formatting changes.

8. Agency-level management and scalability

If you manage email campaigns for multiple clients, look for features built specifically for agency workflows:

• Multi-client dashboards: Manage all client accounts from a single login without constant switching.
  
• White-labeling: Add your branding to reports or dashboards when sharing results with clients.
  
• Lead scoring and ROI tracking: Show measurable impact, not just engagement metrics.
  
• Pre-built workflow templates: Launch campaigns faster using ready-made automations for common client goals.

Not every email platform includes agency-level tools, but if your team handles several clients, these features can make a big difference. 

How to shortlist the best email marketing platform

Now that you know what to look for, it’s time to narrow your options:
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Step 1: Identify goals and KPIs

Start by defining what success looks like for both your agency and clients. 

Are you trying to help clients:

• Grow their subscriber base?
• Recover lost sales from abandoned carts?
• Nurture leads through a longer B2B sales cycle?

Your goals determine which features will matter most. 

For example, a content-focused client might prioritize ease of use and newsletter design. On the other hand, an e-commerce brand will care more about product recommendations and SMS integration.

💡 Tip: Create a simple table listing each client’s top 3 goals and the metrics (KPIs) you’ll use to measure them, like open rate, revenue per email, or reactivation rate. Use it as a checklist when comparing platforms.

Step 2: Map your must-have features

Once you’ve defined your goals, it’s time to get practical. Create a simple feature matrix with three columns:

✅ Must-have – Non-negotiable features your campaigns depend on.

✨ Nice-to-have – Helpful extras that improve efficiency but aren’t critical.

🚫 Don’t-need – Features that add cost or complexity without clear ROI.

This exercise prevents you from paying for enterprise features you'll never use while ensuring you don't compromise on capabilities that directly support your goals.

🛍 If you work with e-commerce clients

They rely heavily on data-driven automations and purchase behavior insights.

Your must-have list might include:

• Native integrations with Shopify, WooCommerce, or BigCommerce
• Pre-built flows for abandoned carts, re-engagement, and post-purchase follow-ups
• Product feed personalization to feature items dynamically
  Revenue attribution dashboards to tie campaigns to actual sales
  
  

💼 If you work with service-based clients

They focus more on relationships, lead nurturing, and client retention.

Your must-have list might include:

• CRM integrations (HubSpot, Pipedrive, Salesforce)
• Personalized follow-up automations based on pipeline stage
• Appointment booking or scheduling integrations
• Strong deliverability and reporting for client updates and newsletters

💡 ​​Tip: When managing multiple clients, create one shared feature matrix in a spreadsheet and tag which clients need which features. If you spot overlaps, you may be able to find a single tool that covers all their needs. 

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Step 3: Shortlist 3-5 options based on business fit

Head to reliable review sites like G2, Capterra, and TrustRadius, and look for patterns in feedback rather than individual complaints—every platform has unhappy customers, but consistent issues across reviews point to real issues. 

Focus on reviews from businesses that look like yours:

• Agencies running multiple client accounts
  
• Small marketing teams juggling content, automation, and analytics
  
• B2B or eCommerce companies with similar goals

A platform loved by enterprise teams might overwhelm smaller agencies, while a simple tool could fall short for clients needing deeper automation.

💡 Tip: Filter your research down to 3-5 strong contenders that best match your feature checklist, budget, and team bandwidth. Anything more than that, and you’ll end up with analysis paralysis.

Step 4: Run free trials before you commit

A free trial is your chance to see how the tool performs in your day-to-day workflow. Most platforms offer 14 to 30 days, so make them count by testing with real data and real tasks, not sample templates.

During your trial:

• Import a small segment of your actual subscriber list.
• Build one full workflow that reflects a real client campaign.
• Connect your key tools—such as CRM, eCommerce store, or analytics.
• Send a test campaign and track deliverability and reporting.
• Pay attention to usability—does the interface feel smooth or clunky?

💡 Tip: Take notes of anything that feels awkward. What feels like a small annoyance during a trial can turn into a major time sink once you’re managing multiple clients and campaigns.

Step 5: Score and compare costs

Once you’ve tested your shortlist, it’s time to put numbers behind your impressions. Create a simple scorecard and rate each platform (1-5) for:

• Core features: How well it meets your must-haves.
• Ease of use: How intuitive it feels for daily tasks.
• Overall experience: How smoothly it fits into your team’s workflow.

Then look beyond the monthly subscription. Consider the total cost of ownership, including:

• Setup and onboarding time
• Training for your team or clients
• Consulting or migration fees
• Add-ons like extra seats or dedicated IPs

❗Note: A $100/month tool that takes 20 hours to manage might cost more in time and effort than a $200/month platform that works immediately. 

Step 6: Run a short pilot before committing

Even after trials and scoring, consider running a 30-60 day pilot with your top choice before migrating your entire operation. 

This reveals issues that might be missed during short trials, like integration bugs, slow automation execution, weak deliverability, or confusing workflows.

Start small: run one campaign type or client project through the platform. Track results closely and ask for feedback from everyone who’ll use it day-to-day.

💡 Tip: If your team runs multiple client accounts, this is the stage to test how easily you can switch between them or duplicate workflows. A smooth pilot now prevents major migration headaches later.‍

🔗 Related article: 11 Best Email Marketing Software for Agencies 

Email Marketing Software Selection Checklist

Use this checklist to evaluate each platform objectively and make a fair, data-driven comparison.

7 mistakes to avoid when choosing email marketing software

❌ Choosing a tool built for the wrong audience. Enterprise platforms are overwhelming for small teams; basic newsletter tools are limiting for larger ones. Always match the platform’s target audience to your agency’s (or your client’s) size and complexity.

❌Paying for features you’ll never use. All-in-one suites sound impressive, but most agencies only use a fraction of what they pay for. Audit your real needs before committing to an expensive plan.

❌ Ignoring deliverability metrics. Beautiful templates and smart automations don’t matter if your emails land in spam. Prioritize platforms with strong deliverability infrastructure and transparent reporting.

❌ Falling for cheap starter tiers. That $10/month plan might cap you at 500 subscribers, 1,000 emails per month, or exclude automation entirely. Calculate costs at your expected 12-month volume, not your current size.

❌ Not testing integrations. Native integrations often work differently than advertised. Test data sync, field mapping, and automation triggers between your email platform and essential tools before committing.

❌ Ignoring support quality. When deliverability drops or automation breaks, you need responsive help. Check whether the platform offers email support, live chat, or phone support—and test response times during your trial.

❌ Letting decision fatigue drive the final choice. After comparing dozens of platforms, it's tempting to just pick one and move on. Use your checklist and evaluation scores to make a data-driven decision rather than an exhausted one.

⚡ Agency Hack: Cut client onboarding emails by 80%  

So far, we’ve focused on how to choose the right email marketing platform for your clients. But before you can send a single campaign, there’s one major bottleneck that slows most agencies down—the onboarding process.

Getting access to your clients’ marketing accounts, whether that’s their email platform, Facebook Ads, Google Analytics, Instagram account, or Shopify store, can be simplified and automated with Leadsie.

With one secure Leadsie link, you can request and receive access to all your clients’ marketing and social accounts in one go. 🔒

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