eM Client vs Mailspring

eM Client brings email and productivity tools together on Windows, macOS, Android, and iOS. Its unified inbox accompanies calendar, tasks, contacts, notes, and chat, with offline access, scheduled sending, calendar tools, and online-meeting integration. It supports Google Workspace, Office 365, Outlook, and Exchange, and provides PGP and S/MIME message encryption. Integrations include Teams, Slack, and Rocket.Chat. The Free plan allows two email accounts on one device and costs nothing; registration is required. Personal costs $39.95 a year and permits unlimited email accounts on up to three devices. Business costs $49.95 a year. One-time options are also listed: Personal Lifetime is $59.95, paid once, and Business Lifetime is $79.95, paid once. Android and iOS versions are free to use without a license. Support options include a user forum and VIP Support. The maker is based in Prague, Czech Republic, and lists a 30% discount for NGOs, schools, and universities.

Mailspring is a desktop email client for Linux, macOS, and Windows, with support for multiple accounts in one inbox. It connects to Gmail, iCloud, Office 365, Fastmail, Outlook.com, Yahoo!, and IMAP/SMTP providers, and indexes email for advanced Gmail-style searches across connected accounts. The client works offline and supports scheduled sending. Its free features include undo send, spell and grammar checking, custom themes, dark mode, and localization. Pro adds read receipts, link tracking, send later, follow-up reminders, templates, contact profiles, snoozing, and mailbox insights. Mailspring connects to mail providers through IMAP and to calendars and contacts through CalDAV and CardDAV, though calendar tools are not included in the app. It can translate drafts into Spanish, Russian, simplified Chinese, French, and German, and offer to translate incoming messages. Mailspring says credentials are kept in the system keychain and email is not processed in the cloud. The free plan is available; Pro costs $8 a month, billed monthly.