Email marketing tools comparison by number of contacts

Quick answer: if you manage between 500 and 20,000 contacts and want to keep costs to a minimum without giving up key features of email marketing, Mailrelay really stands out.

The free account supports up to 20,000 contacts and 80,000 emails a month. It also includes automations, A/B testing, segmentation, analytics and support via chat, tickets and phone.

Beyond 20,000 contacts, the comparison changes.

It’s no longer enough to just look at how much it costs to store a list.

You need to work out how many emails you’ll send, which automations you need and how much support your team requires.

Choosing between different email marketing tools might seem easy when you have few subscribers.

However, the differences grow as your database expands.

A platform that’s cheap with 500 contacts can become far too expensive with 50,000.

Likewise, a free account might store thousands of contacts, but prevent you from sending a full campaign in a single day.

That’s why this email marketing tools comparison looks at Mailrelay, Mailjet, MailerLite, Acumbamail, Brevo, Mailchimp and Klaviyo from a practical perspective: how many contacts you have and how much you need to send.

Last updated: August 2026. The limits and plans listed reflect the terms published by each provider and checked on that date. Prices may change over time.

Summary: what to look for based on your list size

Which email marketing tool to choose based on your number of contacts

The number of contacts is important, but it shouldn’t be your only baseline.

Before signing up for one of the many email marketing tools, also work out how often you’ll send.

A company with 10,000 contacts sending a monthly newsletter needs 10,000 emails. Another with the same list and eight monthly campaigns needs 80,000.

These are two very different needs.

It’s also worth checking what features are included in each pricing tier. Automations, A/B testing, segmentation, analytics, or support might be available with one provider but reserved for higher-tier plans with another.

Mailrelay as an email marketing platform takes a particularly competitive approach here. Its free account lets you store up to 20,000 contacts and send up to 80,000 emails a month.

It also includes all the key features for your email marketing.

These include the AI email editor, segmentation, custom fields, A/B testing, landing pages, forms, reports, visual automations, webhooks and a REST API.

This means Mailrelay’s free plan isn’t just for taking a quick look at the dashboard.

You can use it to develop a real email marketing strategy for quite some time before needing a higher-tier plan.

Additionally, chat, ticket, and phone support is also available on the free account. On paid plans, it upgrades to priority support.

Email marketing tools comparison: pricing, free plans, and features

This table summarizes the most important differences between the main email marketing tools in the comparison.

This email marketing tools comparison reveals something important.

“Free” doesn’t mean the same thing on every platform

Brevo, for example, lets you store up to 100,000 contacts for free. However, you can only send 300 emails a day from that account. A campaign aimed at thousands of subscribers would have to be spread over several days.

Mailjet allows 6,000 free monthly emails, with a maximum of 200 daily and 1,000 contacts.

MailerLite changed its free plan on June 16, 2026. Its current limit is 250 active subscribers and 2,500 monthly emails.

Mailchimp currently limits its Free plan to 250 contacts and 500 monthly emails. Klaviyo also applies a maximum of 250 profiles, with 500 emails a month.

By contrast, Mailrelay’s free account allows 20,000 contacts and 80,000 emails a month.

Of the tools we analyze here, it offers by far the largest sending capacity.

Email marketing tools for lists of 500 to 20,000 contacts

This is where the biggest differences between email marketing tools become apparent.

To compare each volume properly, we’ll assume you need to send regular newsletters to a good part of your list.

From 500 to 1,000 contacts

With 500 contacts, Mailrelay still offers plenty of headroom within its free plan.

Mailjet also lets you work for free, as its Free account accepts up to 1,000 contacts. However, there’s a limit of 200 daily emails.

Brevo can store the list without issues, but its 300 daily emails prevent you from sending a newsletter to 500 people simultaneously on the free plan.

MailerLite, Mailchimp, Acumbamail, and Klaviyo already exceed their current free limits when the list reaches 500 contacts.

So, for a company with between 500 and 1,000 contacts, Mailrelay is especially attractive if it wants to grow without having to start paying soon.

From 1,001 to 2,500 contacts

In this bracket, the advantage of Mailrelay’s free account grows.

Mailjet requires you to upgrade from the Free plan when you surpass 1,000 contacts. Its Starter plan supports 2,000 contacts and 8,000 emails for $9 a month, while Essential starts at $17 for 15,000 emails and allows unlimited contacts.

MailerLite also requires a paid plan once you exceed 250 subscribers. Its entry-level plan currently starts at $12 a month for 500 subscribers.

Mailchimp, Klaviyo, and Acumbamail also require a paid tier in this bracket.

Mailrelay, on the other hand, stays within its free limits.

From 2,501 to 5,000 contacts

Once you reach 5,000 contacts, you’re building a substantial list.

Because of this, it’s not a good idea to choose an email marketing tool based solely on the first month’s price.

You need automation, analytics, and the ability to segment.

MailerLite is appealing for newsletters and creators. Its plans scale by subscribers. On its Comfort tier, the monthly sending limit is ten times the maximum of your contracted bracket. With 5,000 subscribers, that would be 50,000 monthly emails.

Mailjet can be competitive for large lists with low sending frequency, because its Essential plans support unlimited contacts and charge mainly based on email volume.

Brevo also uses an approach heavily tied to sending volume. Its Starter plan begins at $9 a month and Standard at $18, though the cost increases based on your contracted needs.

However, Mailrelay still lets you keep 5,000 contacts for free and send up to 80,000 emails a month.

That leaves plenty of room for newsletters, promotions, and automations without adding a fixed cost.

From 5,001 to 10,000 contacts

A list of 10,000 contacts can transform the cost of some email marketing tools.

Platforms whose pricing increases mainly with subscriber count tend to bump you up to a new tier as your database grows.

Mailchimp works this way. The price for Essentials and Standard depends on your total contracted contacts. Essentials allows up to 50,000 contacts and Standard up to 100,000.

Klaviyo also scales based on profiles and capacity, though in return it offers a platform highly focused on customer data, attribution, and ecommerce integrations.

Mailrelay is still free with 10,000 contacts as long as you don’t exceed 80,000 emails a month.

Simply put, that limit allows up to eight full sends to a list of 10,000 contacts each month, provided each message counts as a single email.

For an SMB sending one or two weekly newsletters, this can cover a highly significant portion of their needs.

From 10,001 to 20,000 contacts

This is probably the bracket where Mailrelay differs most from many email marketing tools.

With 20,000 contacts you can stay on its free account and have 80,000 monthly emails at your disposal.

That equals four full monthly campaigns for a list of 20,000 contacts.

Plus, Mailrelay maintains features like segmentation, automations, A/B testing, an AI editor, reports, and technical support.

Therefore, the savings don’t just come from storing contacts for free.

It also saves you from upgrading to a higher plan just to access features that are standard in a professional email marketing strategy.

Mailjet, for example, reserves automations, advanced analytics, and A/B testing for Premium.

Brevo includes automation for up to 2,000 contacts on its Free plan. For unlimited automation, you have to upgrade to at least Standard.

Mailchimp doesn’t include its premium automation workflows in the current free plan either.

Thus, when comparing email marketing tools for 20,000 contacts, you have to evaluate both the volume and the included features.

Email marketing tools for lists of 20,000 to 100,000 contacts

Surpassing 20,000 contacts changes the game.

For Mailrelay, this is where the free plan ends, but the platform maintains a structure designed to scale your sending volume.

From 20,001 to 50,000 contacts

Mailrelay offers a tier of 250,000 monthly emails for databases of up to 50,000 contacts.

If you max out your 50,000 contacts, you can still email your entire list five times a month.

It’s a simple baseline for comparing the true cost across email marketing tools.

Don’t just ask how much 50,000 contacts cost.

Ask how much it costs to send to those 50,000 contacts five times and which features will be included.

This distinction is important on platforms like Mailjet or Brevo, where sending volume heavily impacts pricing.

MailerLite, Mailchimp and Klaviyo are more closely tied to audience size or the number of active profiles. So a growing list can mean moving up to higher tiers even if you don’t increase your sending frequency at the same rate.

Mailrelay adds another operational advantage: on paid plans it uses a priority queue and priority support via chat, tickets, and phone.

With tens of thousands of subscribers, having specialized support can be just as important as saving a few bucks on your subscription.

From 50,001 to 100,000 contacts

With 100,000 contacts, we’re talking about high-volume email marketing.

Mailrelay offers a capacity of 500,000 emails a month for up to 100,000 contacts.

Again, that equates to roughly five full monthly campaigns for a base of 100,000 contacts.

At this size, you need to evaluate deliverability, bounce management, list cleaning, analytics, segmentation and support.

The complexity of your automations matters too.

Klaviyo makes a lot of sense for ecommerce businesses that need to heavily leverage customer data and revenue attribution. Its platform offers segmentation, automations, reporting, and ecommerce-focused integrations.

Mailchimp offers Standard up to 100,000 contacts and Premium for even larger audiences, with enhanced automation and support capabilities depending on the plan.

Mailjet provides plans based primarily on volume. Premium incorporates automation, A/B testing, and advanced analytics, and tiers of 100,000 emails or more can include a dedicated IP.

Mailrelay is especially appealing when you need bulk email campaigns, simple automation and controllable costs, without adding complexity your company won’t use.

What features to compare besides email marketing tool pricing

A good email marketing tools comparison shouldn’t stop at a pricing table.

The lowest price tag can become expensive if you later need another tool, hours of setup, or external technical help.

Automation

Not all companies need to use hundreds of conditions.

Many simply require a welcome series, follow-up emails, drip campaigns, birthday triggers, cart recovery, or responses based on groups and tags.

Mailrelay covers these scenarios through a visual editor with triggers, conditions, branches, webhooks, and automated actions.

Segmentation

As a list grows, sending the exact same content to everyone generally makes less and less sense.

Mailrelay lets you use groups, tags, segments, custom fields, and lead scoring. We also offer automated list cleaning.

A/B testing

Testing subject lines or senders helps you make data-driven decisions. In Mailrelay, this feature is part of the toolkit available across all plans, including the free one.

Analytics and reporting

Mailrelay shows deliveries, bounces, opens, clicks and click maps, among other email marketing metrics and statistics that let you analyze each campaign.

Support

When working with 500 contacts, a glitch can be annoying.

When you have 100,000, it can directly compromise a major sales campaign.

Mailrelay offers support via chat, tickets and phone, even on the free plan.

By comparison, Mailjet limits free ticket support to the initial 30-day period. MailerLite offers live support during its 14-day premium trial, then points free users toward self-service resources.

Mailchimp provides email support during the first 30 days of the free plan. Klaviyo offers email support during the first 60 days of its Free plan.

That’s why support has to be part of the total cost calculation for any email marketing tool.

Why Mailrelay stands out when comparing email marketing tools by volume

Mailrelay’s main strength lies in three key parameters: volume, features, and cost.

Up to 20,000 contacts, the free account lets you run email marketing campaigns with a capacity that’s hard to match among the analyzed competitors: 80,000 monthly emails.

This isn’t just an account to test the editor.

It includes automation, A/B testing, segmentation, forms, landing pages, analytics, an editor with AI features, REST API and SMTP, webhooks, and integrations.

Furthermore, it maintains human support via phone, chat, and tickets right from the free plan.

Once the list passes 20,000 contacts, the pricing structure follows a straightforward ratio between contacts and sending capacity.

Among other tiers, Mailrelay offers 250,000 emails for up to 50,000 contacts and 500,000 emails for up to 100,000 contacts. You can check the current pricing and sending capacities.

This makes it easier to forecast the volume a company needs.

However, no email marketing tools comparison should conclude that there’s one perfect platform for everyone.

Klaviyo might be better suited for ecommerce with highly advanced data and personalization needs.

Mailjet can be a good fit when you want to decouple database size from sending volume.

Brevo is appealing for companies looking for a multichannel platform with CRM capabilities.

MailerLite is convenient for creators and newsletter-focused businesses.

Mailchimp provides a vast ecosystem and numerous integrations.

Acumbamail provides another Spanish alternative with different subscription models.

But when the priority is sending high-volume email marketing while keeping costs low and retaining support and essential features, Mailrelay offers a proposition that’s hard to match.

And that advantage is obvious from a list of 500 contacts up to one with 20,000, where it can still be used for free.

Beyond that, up to 100,000 contacts, Mailrelay maintains a sending capacity structure designed to scale alongside larger-volume campaigns.

Conclusion: contact volume isn’t enough to choose an email marketing tool

The best email marketing tool isn’t necessarily the one with the lowest entry price.

The comparison should be made with three figures on the table: contacts stored, emails you’ll send each month and features included in the plan.

For lists of up to 20,000 contacts, Mailrelay stands out in this comparison for combining a high free volume with automation, segmentation, A/B testing, analytics, and support. From there on, it’s worth calculating the cost for full campaigns and taking a close look at deliverability, support, and automation capabilities.

If you want to run your own numbers, check out Mailrelay’s plans and pricing and compare them with how often you actually send.

FAQs about email marketing tools and contact volume

What is the best email marketing tool for 500 contacts?

Mailrelay is a highly competitive option for 500 contacts because that volume falls well within its free account.

You can manage up to 20,000 contacts and send up to 80,000 monthly emails without paying an email marketing subscription.

Mailjet also supports 500 contacts for free, although it applies a 200-email daily limit. MailerLite, Mailchimp, Klaviyo, and Acumbamail currently cap their free plans at 250 contacts or subscribers.

What is the best email marketing tool for 5,000 contacts?

It depends on how many emails you send.

For a company aiming to keep costs low, Mailrelay stands out because 5,000 contacts still fit in its free plan of up to 20,000 contacts and 80,000 monthly emails.

Mailjet and Brevo can be interesting if you prefer to pay primarily for sending volume.

Which email marketing tool is best for 10,000 contacts?

With 10,000 contacts, Mailrelay lets you keep using its free account.

If you send a full campaign to the entire list, each newsletter consumes roughly 10,000 of the 80,000 available emails. Therefore, you would have the theoretical capacity for eight full monthly campaigns.

Can you do email marketing for free with 20,000 contacts?

Yes. Mailrelay lets you store up to 20,000 contacts and send up to 80,000 monthly emails on its free account.

With a 20,000-contact base, that volume allows for approximately four full monthly campaigns to the entire list.

Is Brevo free for large lists?

Brevo lets you store up to 100,000 contacts on its free plan.

However, sending is limited to 300 emails daily. Additionally, free automations support up to 2,000 contacts.

Because of this, storing 50,000 contacts for free doesn’t mean you can instantly send a newsletter to all 50,000.

What’s the difference between paying per contact and paying per email?

A contact-based model increases mainly based on audience size.

A sending-based model depends more on the actual number of emails you send.

That’s why you have to calculate both numbers when comparing email marketing tools.

A list of 100,000 contacts with one monthly send can cost very differently from one that receives five campaigns a month.

Which email marketing tool should you choose for 50,000 contacts?

With 50,000 contacts, it’s wise to compare the cost of several full campaigns, not just storage.

Mailrelay provides a tier of 250,000 monthly emails for up to 50,000 contacts. That represents the capacity for roughly five full monthly campaigns.

Mailjet and Brevo also deserve a comparison in this bracket due to their volume-driven models.

What email marketing platform should you use for 100,000 contacts?

For 100,000 contacts you need to evaluate deliverability, monthly capacity, segmentation, automations, reporting, and support.

Mailrelay offers a tier of 500,000 emails a month for up to 100,000 contacts.

Mailchimp allows up to 100,000 contacts in Standard, while Mailjet has Premium and high-volume plans. Klaviyo can be particularly interesting when ecommerce and heavy data use justify a more specialized platform.

What should you look for in an email marketing tools comparison?

You should review five elements:

• Number of contacts
• Monthly emails
• Features
• Support
• And scaling costs.

You should also check automations, A/B testing, segmentation, analytics, and integrations.

The entry price alone doesn’t tell you how much you’ll end up paying.

Which email marketing tool lets you scale the longest without paying?

Among Mailrelay, Mailjet, MailerLite, Acumbamail, Brevo, Mailchimp, and Klaviyo, Mailrelay offers the largest combination of free contacts and monthly emails in this comparison: up to 20,000 contacts and 80,000 emails a month.

That’s why it’s particularly appealing for projects that want to build email marketing into a reliable channel before taking on high fixed costs.