eM Client vs Thunderbird

eM Client and Thunderbird both land on Worth it.

eM Client

Worth it

Confidence: Low

Buy if you want a free, polished desktop email client to replace Outlook or Thunderbird.

Worth it

Confidence: Medium

Buy if you want a free, open-source desktop client that unifies several email accounts.

eM Client versus Thunderbird
Compare	eM Client	Thunderbird
Verdict	Worth it	Worth it
Best for	Outlook refugees on Windows or Mac	Multi-account power users
Who it's not for	Teams needing shared inboxes or admin controls (Guess: it's a per-device client)	Webmail-first Gmail/Outlook users . redundant layer
Privacy	No known public vulnerabilities found in the sources reviewed.^⁵	Actively maintained: regular Mozilla advisories and 2026 CVE fixes, including an emergency zero-day patch.¹⁴
Public sentiment	Users on Reddit praise eM Client as a well-integrated, fantastic Outlook replacement.^⁴	Opinions split: G2 users consistently praise it while Reddit threads and Trustpilot reviews grumble about early friction.^⁷
Biggest gotcha	No public security page found during review . ask support before business use^⁵	Critical zero-days affecting Thunderbird have required emergency patches¹⁴

Teams needing shared inboxes or admin controls (Guess: it's a per-device client)
Browser-only users who don't want a desktop app
Mobile-first users . no mobile app in evidence
Enterprises wanting centralized mail management (Guess)