Apps similar to Claws Mail include Thunderbird, which is free and open source. Other options are K-9 Mail, Betterbird, FairEmail and Microsoft Outlook. There's no shortage of Email Clients like Claws Mail, with more than 50 alternatives for Windows, Linux, Mac, Android and the web.
The free Zimbra Desktop client allows you to meld the online and offline worlds – storing and synching your email, calendar, contacts, files and documents in the cloud, yet having them locally accessible when on the road.
United States
The Bat! is a secure email client software, built to protect your correspondence against third-parties.
Moldova
Wino is a lightweight native mail client for Windows 10/11. It is still in active development. Main motivation for this project is to replace Mail & Calendar for Windows with modern Windows design without using web technologies for speed.
Türkiye
Mac IMAP email client featuring keyboard control, Markdown email composition, advanced search capabilities, smart mailboxes, automatic signature handling, cryptographic options with OpenPGP/S-MIME, tagging, multiple notifications, and customizable layouts including widescreen.
Foxmail is a free POP3 and IMAP4 e-mail client in English and Chinese for Windows systems.
China
Productivity-centered email application streamlines inbox management, uses AI for drafting responses, automates snippets, summarizes conversations, enables timely sends, integrates calendar and CRM, and includes collaborative features like live views and comments.
United States
Eclipse Mail is a fork of Interlink Mail and News made for Windows XP and runs on IA-32 i686 platforms. Some advantages over upstream and roytam1's mailnews are more optimizations and better interoperability with upstream.
Historically, Icedove was a re-branding of Thunderbird by the Debian project, with minimal modifications, in order to resolve branding disputes. Debian since discontinued Iceweasel in February of 2017 after reaching an agreement with Mozilla over the use of it's trademark.
Mail is designed to let you manage your email quickly and effortlessly. Its interface is based on conversations, so you can read an entire discussion without having to click from message to message.
United States
An enterprise application server that integrates information into a single workspace, integrates also a full mail server
India
Japan
Paraguay
