saasrankedSoftware, ranked on the facts

email client · Claws Mail project

Claws Mail

Lightweight open-source mail client with IMAP, POP3 and GnuPG, free for Windows and Linux.

61/100

#8 of 10 email clients
Facts checked 8 Oct 2026

In short

Claws Mail suits people who want a free, light client with filters, templates, GnuPG and S/MIME2,4,8. The catch: Gmail and Microsoft sign-in needs you to register your own app first, Exchange works only through IMAP, and the pages show no unified inbox or delayed send, with a calendar only through a plugin2,5,6,7.

Best for: People who want a small, keyboard-friendly client with strong filtering and PGP.

Where the points come from

Mail and accounts14 of 27
Calendar and contacts0 of 9
Privacy and encryption19 of 28
Systems and upkeep7 of 15
Price21 of 21

Mail and accounts 14 of 27 points

RuleWhat is publishedPoints
Account typesIMAP, POP3, Gmail and Microsoft 365 sign-inIMAP and POP32; OAuth2 for Gmail and Microsoft6; Exchange only through IMAP, no EWS or Graph7.9 / 12
Unified inboxNot publishedNot published on the vendor's features page or interface FAQ2,11.0 / 4
Mail toolsTemplatesFeatures page lists templates, message queueing and drafting; no scheduled send, snooze or undo send2.2 / 8
Filters and rulesYesFiltering rules can run when mail is received, if the account option is on8,2.3 / 3

Calendar and contacts 0 of 9 points

RuleWhat is publishedPoints
Built-in calendarNot publishedPlugins page mentions a personal calendar but not a calendar view or creating events5.0 / 6
CalDAV and CardDAVNot publishedPlugins page lists webCal subscriptions; CalDAV and CardDAV are not mentioned5,2.0 / 3

Privacy and encryption 19 of 28 points

RuleWhat is publishedPoints
OpenPGPYesFeatures page lists GnuPG support; plugins page lists PGP/Inline and PGP/MIME plugins2,5.7 / 7
S/MIMEYesWindows page says the S/MIME plugin is integrated with the main download; FAQ shows setup with your own certificate4,5,9.6 / 6
Blocks tracking pixelsNot publishedFeatures page lists configurable image display; the default is not stated2,11.0 / 4
Open-source appsYesHome page says Claws Mail is distributed under the GPL1.6 / 6
Mail stays on your deviceNot publishedFAQ says mail is stored in a local folder; no page states it avoids vendor servers10.0 / 5

Systems and upkeep 7 of 15 points

RuleWhat is publishedPoints
Other systemsLinuxDownloads page lists Linux packages and BSD ports; no macOS, iOS, Android or web version3.2 / 10
Released in the last yearYesVersion 4.4.0 released 9 March 2026; Windows 4.4.0-1 installers are listed3,4.5 / 5

Price 21 of 21 points

RuleWhat is publishedPoints
No ads in the appYesOpen-source app under the GPL1.3 / 3
Free planYesGPL software offered as a download with no price shown. Read as free1,3.6 / 6
Cost of a year$0No price is charged on the vendor's pages; the full app is a free download3.12 / 12

The rule behind each line: how we score email clients.

Plans and prices

As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.

PlanPrice as listedPer monthNotes
Free1 personFree1,3$0GPL software; no price shown

Strengths

  • Free to download, released under the GPL1,3.
  • Has filtering, templates and GnuPG support, and the PGP and S/MIME plugins come with the Windows download2,4,5.
  • The Windows installers for 4.4.0 are 32-bit and 64-bit4.
  • Filters can run when mail arrives or by hand on a folder8.

Limits

  • OAuth2 for Gmail and Microsoft needs you to create your own Google Cloud or Microsoft Entra app6.
  • Exchange is reached only through IMAP; the FAQ says MAPI is not supported7.
  • A calendar is limited to a plugin that handles vCalendar messages and webCal subscriptions5.
  • No Mac, iOS, Android or web app is listed on the download page3.
  • The features page lists no scheduled send, snooze or undo send2.

Other email clients

  1. 1
    Mozilla ThunderbirdPeople who want a free, open-source client with built-in encryption
    88/100
    $0cost of a year
  2. 2
    BetterbirdThunderbird users who want more control over how mail is listed, sorted and searched
    78/100
    $0cost of a year
  3. 3
    BlueMailPeople who want a free app with PGP, a calendar and many accounts
    78/100
    $0cost of a year
  4. 4
    eM ClientPeople who want PGP, S/MIME and a calendar in one paid Windows app
    73/100
    $55.87/yrcost of a year

All 10 email clients

Sources

  1. Claws Mail, Claws Mail project. Accessed 8 Oct 2026.
  2. Claws Mail features, Claws Mail project. Accessed 8 Oct 2026.
  3. Claws Mail downloads, Claws Mail project. Accessed 8 Oct 2026.
  4. Claws Mail for Windows, Claws Mail project. Accessed 8 Oct 2026.
  5. Claws Mail plugins, Claws Mail project. Accessed 8 Oct 2026.
  6. Oauth2 (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.
  7. Connecting to MS Exchange (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.
  8. Filtering and Processing of Messages (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.
  9. S/MIME howto (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.
  10. General Information (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.
  11. Interface (Claws Mail FAQ), Claws Mail project. Accessed 8 Oct 2026.

Website: www.claws-mail.org · Markdown version · We are not affiliated with Claws Mail project.