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SeaMonkey Mail

Free#63 of 145 in Web Browsers

SeaMonkey Mail: A free, open-source desktop mail client with tabs, filtering, feeds, and LDAP support. Ranked #63 of 145 in Web Browsers by our editors (4.2/10); pricing: Free plan; best for users needing an open-source mail client.

4.2/10Editor score
Visit SeaMonkey
SeaMonkey Mail4.2 Visit SeaMonkey

At a glance

  • Editor score
    4.2 / 10
  • Pricing
    Free plan
  • Best for
    Users needing an open-source mail client
  • Free plan
    Yes
  • Paid from
    Free
  • Browser engine
    Gecko
  • Founded
    2005 · Germany
  • Facts checked
    19 Sep 2026
SeaMonkey Mail screenshot

  • Where it wins

    • Supports multiple accounts, mail tags, views, and tabbed messaging
    • Includes adaptive junk-mail filtering and web-feed reading
    • Offers S/MIME and LDAP address-book support across three desktop platforms

  • Where it doesn't

    • Its focus is messaging rather than web browsing
    • It is distributed as part of the broader SeaMonkey suite
    • May not suit users seeking a browser-first product

Our verdict on SeaMonkey Mail

SeaMonkey Mail is the email and newsgroup component of the SeaMonkey Internet Application Suite. It is designed for desktop users who want an open-source messaging client on Windows, macOS, or Linux. The project is distributed free of charge, and its source code is published under the Mozilla Public License 2.0. Alongside email and newsgroups, it includes web-feed reading and support for multiple accounts, making it suited to users who want several communication tools in one desktop suite.

Its strongest area is the combination of everyday mail organization and account management. Adaptive junk-mail filtering helps address unwanted messages, while mail tags and mail views provide ways to organize correspondence. Tabbed messaging keeps multiple conversations or message views within the same interface. S/MIME support adds an option for message security, and LDAP address-book support connects the client with LDAP-based contact directories. Add-on and extension management also gives the suite a way to manage supplementary functionality.

SeaMonkey Mail is a focused choice for users prioritizing open-source desktop email, newsgroups, feeds, and established account features. It should appeal to people who value multiple account support, filtering, tabs, and LDAP integration across major desktop operating systems. It is less suitable for someone evaluating products primarily as web browsers: Mail is presented as a messaging component, while web browsing belongs to the wider SeaMonkey Internet Application Suite. Users seeking a browser-first product should consider a dedicated web browser instead.

Your product? Our editors can test SeaMonkey Mail in depth and publish a review, labelled as paid · from $149/mo →

SeaMonkey Mail pricing

Plans Free planFree Free to use — no paid tier required for the core job.
See plans on seamonkey-project.org

SeaMonkey Mail fact sheet

Free planYes
Paid fromFree
Supported platformsBoth
Browser engineGecko
Built-in ad blockingNot verified
Tracking protectionNot verified
Extension supportOwn_store
Cross-device syncNot verified
Open sourceYes
DeploymentDesktop
PlatformsWindows, macOS, Linux
Integrations1 integrations: LDAP
PricingFree plan
Websiteseamonkey-project.org
Facts checked19 Sep 2026

SeaMonkey Mail integrations

SeaMonkey Mail lists 1 integrations on its own site.

  • LDAP

Alternatives to SeaMonkey Mail

See all SeaMonkey Mail alternatives →

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Featured on iTechGuides

Featured on iTechGuides — SeaMonkey Mail 4.2/10

SeaMonkey Mail is listed in our Web Browsers directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Sep 2026

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