Best of · Free and Open Source Email

The best free and open source email software

Free email splits two ways: a hosted free tier you sign up for in minutes, or open source you run yourself for full control and no fees. We weighted cost, ease, what the free tier actually includes and how much you own, then ranked the six best of both routes.

Reviewed by M. HALLORAN·Updated MAY 2026·How we vet
Tools compared 6
Criteria weighted 5
Last reviewed June 2026
Paid placements 0
How we ranked the field

Free splits two ways: a hosted free tier you sign up for, or open source you host yourself. We scored both on cost, ease of use, what the free option really includes, and how much control and ownership you keep. See the full rubric →

Free or open cost 30%
Ease of use 25%
Free tier features 20%
Control and ownership 15%
Deliverability 10%
01
RANK
★ Editor’s Choice

Brevo

Best for a no cap free tier

The most generous free tier in the field: 300 emails a day with no limit on how many contacts you store, plus automation and SMS in the paid tiers when you outgrow it. The editor is plainer than the design led tools, but for free, nothing matches the headroom.

  • No contact cap free
  • Email and SMS
  • Bills by sends
Read the Brevo verdict → From $9/mo · free plan
90
OUT OF 100
02
RANK

Kit

Best free tier for creators

Free up to 10,000 subscribers with unlimited emails, Kit is the obvious pick for a newsletter or a creator selling their own work. The free plan limits you to one automated sequence, and the design is deliberately minimal.

Read the Kit verdict → From $39/mo · free plan
88
OUT OF 100
03
RANK

Mautic

Best open source overall

Mautic is full marketing automation under a free, open license, with no contact fees and no feature gates, hosted on your own server. You get campaigns, lead scoring and segmentation that rival paid suites. The catch is real: you provide the server, the setup and the upkeep.

Visit Mautic ↗ Open source · self hosted Free · open source
84
OUT OF 100
04
RANK

MailerLite

Best free tier for design

The cleanest editor here, free to start, so a small sender can ship a good looking campaign fast. Note the 2026 free tier is thinner than it was, now 250 subscribers and 2,500 monthly emails, so heavier senders move to the low cost paid plan.

Read the MailerLite verdict → From $10/mo · free plan
83
OUT OF 100
05
RANK

Listmonk

Best open source for volume

A single binary that sends bulk campaigns at high speed and manages millions of subscribers on one server, free and open source. It is a focused sender, not a full automation suite, and it expects a technical hand to run it.

Visit Listmonk ↗ Open source · self hosted Free · open source
81
OUT OF 100
06
RANK

Omnisend

Best free tier for stores

If you run a store, Omnisend's free plan gives 250 contacts and 500 emails a month with full ecommerce automation, a fast way to test selling by email. Outside ecommerce it is more tool than you need, and SMS is now gated higher.

Read the Omnisend verdict → From $16/mo · free plan
80
OUT OF 100

Pricing verified as of June 2026. Vendors change plans often · check the vendor for current pricing.

At a glance

✓ full  ·  ∼ partial  ·  — none
Capability BrevoKitMauticMailerLiteListmonkOmnisend
Free to use
Marketing automation
Native SMS
Open source
Open REST API