Comparison

Mailspring vs Mozilla Thunderbird

No leader: the top candidate Mailspring has only 0.29 confidence (low), below the 0.35 needed to declare a winner. The attribute-by-attribute breakdown below, with a source and date on every value, is the honest way to compare them.

Machine formatsJSONMarkdownGraphQLor send Accept: application/json
Mailspring66
Mozilla Thunderbird60
Score
Vioscale score
Mailspring66 / 100low · 29%updating
Mozilla Thunderbird60 / 100low · 27%updating
Pricing
Free tier
Mailspring
Mozilla Thunderbird
Model
Mailspringcommercial
Mozilla Thunderbirdfreemium
Price level
Mailspringlow
Mozilla Thunderbirdfree
Starting price
Mailspring$8
Mozilla Thunderbird
Transparent
Mailspring
Mozilla Thunderbird
Integrations
Count
Mailspring7
Mozilla Thunderbird
Security
Scorecard
Mailspring
Mozilla Thunderbird7.2
Adoption
Dependent repos
Mailspring
Mozilla Thunderbird0
Github stars
Mailspring17,762
Mozilla Thunderbird13,921
Activity
Commits last 30d
Mailspring38
Mozilla Thunderbird100
Release
Cadence days
Mailspring15
Mozilla Thunderbird
History
Mailspring20 items
Mozilla Thunderbird20 items
License
Spdx
MailspringGPL-3.0
Mozilla ThunderbirdApache-2.0
Language
Primary
MailspringJavaScript
Mozilla ThunderbirdKotlin
Market
Availability
Mozilla Thunderbird

Capabilities

Feature-by-feature on the axes that matter for email clients. “-” means undocumented, not absent.

Capabilities
Deployment model
MailspringLocal direct imap client
Mozilla ThunderbirdLocal direct imap client
Universal imap smtp exchange support
Mailspring
Mozilla Thunderbird
Keyboard shortcut only navigation speed
Mailspring-
Mozilla Thunderbird-
Split inbox AI auto categorization
Mailspring-
Mozilla Thunderbird-
Read receipts and open tracking
Mailspring
Mozilla Thunderbird-
Snooze and scheduled send later
Mailspring
Mozilla Thunderbird-
Generative AI LLM email drafting
Mailspring-
Mozilla Thunderbird
Conversational chat layout view
Mailspring-
Mozilla Thunderbird-
Unified multi account inbox view
Mailspring
Mozilla Thunderbird
Pgp end to end encryption support
Mailspring-
Mozilla Thunderbird-
SOC2 type ii
Mailspring-
Mozilla Thunderbird-
ISO 27001
Mailspring-
Mozilla Thunderbird-
Pricing model
MailspringFreemium
Mozilla ThunderbirdFree open source

What each one is

The product in its own terms, so the numbers below have context.

Mailspring

A lightweight desktop application for Mac, Windows, and Linux that brings together multiple email accounts from different providers into one unified inbox. Core features run locally on your computer, with optional paid features for message tracking, scheduling, and productivity analytics.

Independently observed

Mozilla Thunderbird

Thunderbird consolidates email, calendars, and contacts from multiple accounts into one interface. It runs on Windows, Mac, and Linux, is funded by user donations, and prioritizes privacy by never collecting personal data or serving advertisements.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Mailspring

from $8/mofreemiumFree tier

Free tier available; Pro at $8/month

  • FreeFree
    • Multi-account support
    • Unified inbox
    • Snooze
    • Send later
    • Mail rules
    • +4 more
  • Pro$8/month
    • Read receipts
    • Link tracking
    • Unlimited snooze and send later
    • Mailbox analytics
    • Contact and company profiles
as of verify ↗

Mozilla Thunderbird

FreeFree tier

Free, open-source. Free forever.

as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
macOS
Mailspring
Mozilla Thunderbird
Windows
Mailspring
Mozilla Thunderbird
Linux
Mailspring
Mozilla Thunderbird

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Mailspring

8 total
  • Gmail
  • iCloud
  • Office 365
  • FastMail
  • Outlook.com
  • Yahoo!
  • IMAP
  • SMTP
Independently observed

Mozilla Thunderbird

Not documented yet.

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.