Mozilla Thunderbird vs Spike

Mozilla Thunderbird is a free, open-source email application for Windows, Linux, macOS, and Android. Users can manage multiple accounts separately or combine them in a unified inbox. The app includes calendar, contacts, and task tools; desktop users can also work offline and schedule messages. Its interface is customizable, and it supports third-party add-ons. Thunderbird says it does not put ads in the inbox or sell inbox advertising, and that user donations fund the project. It describes privacy and security as priorities and says its open-source code has been reviewed and improved over 20 years. The application is part of MZLA Technologies Corporation, owned by Mozilla.org. Help and getting-started resources are available for desktop and mobile users, with contributors around the world supporting the project. Thunderbird is available free forever, with donations optional; its listed mobile platform is Android.

Spike combines email, calls, notes, tasks, and to-dos in a single hub, and presents email threads as chat-like conversations. It has a unified inbox, scheduled sending, and calendar tools, and runs on Android, iOS, macOS, web, and Windows. Spike AI can draft messages and replies, summarize conversations, and provide an assistant; free tiers list 10 queries for several AI features. Teamspace adds channels, shared inboxes, groups, collaborative documents and tasks, and audio and video meetings. Spike works with existing accounts such as Gmail, Office 365 or Outlook, Exchange, iCloud, Yahoo, and other IMAP accounts. Cloud attachments can use Google Drive, Dropbox, or OneDrive, and calendars can connect with Google Calendar, Outlook, and Apple Calendar. Spike says it encrypts messages with AES-256 using a per-message private key, and undergoes periodic external security audits. The Email App Free plan includes one address, 60 days of search history, 1 GB storage, and 30 MB file uploads. Email App Pro is $6 a month billed annually; Ultimate is $12 a month billed annually.