Comparison of email clients


The following tables compare general and technical features of a number of notable email client programs.

General

Basic general information about the clients: creator/company, O/S, licence, & interface. Clients listed on a light purple background are no longer in active development.
ClientAuthor/Developer[|Operating system]Software licenseUser Interface
AlpineUniversity of WashingtonCross-platformTUI
Apple MailApplemacOS, iOS, watchOSGUI
BalsaStuart ParmenterLinuxGUI
Becky! Internet MailRimartsWindowsGUI
BlitzMailDartmouth CollegeGUI
Citadelcitadel.orgUnix-likeWebmail
Claws Mailthe Claws Mail teamCross-platformGUI
ConeCourier Mail Server developersUnix-likeTUI
Courier Micro Computer Systems, Inc., continued by Rose City SoftwareWindowsGUI
ElmDave Taylor, Sydney Weinstein, Bill Pemberton, Michael Elkins, Kari HurttaUnix-likeTUI
eM ClienteM Client Inc.Windows,
macOS		GUI
EmailTrayInternet Promotion Agency S.A.Windows, AndroidGUI
Eudora OSEQualcommWindows, macOSGUI
Eureka EmailSean O'ConnorWindowsGUI
EvolutionThe GNOME ProjectUnix-likeGUI
FirstClassOpen TextGUI
Forté AgentMark SidellWindowsGUI
GearyYorba FoundationUnix-likeGUI
GNUMailLudovic Marcotte and othersUnix-like, macOSGUI
GnusGnus teamCross-platformTUI and GUI
GroupWiseMicro Focus Cross-platformGUI
HiriHiriCross-platformGUI
i.Scribe, InScribeMemecodeWindows, macOS, LinuxGUI
IBM Notes IBM Collaboration Solutions, IBMWindows, macOS, LinuxGUI, Web and Mobile
IMPHorde LLCCross-platformWebmail
K-9 MailK-9 Dog Walkers: cketti, et al.AndroidGUI
KMailKDECross-platformGUI
MailbirdMailbirdWindowsGUI
MailpileMailpileLinux, Windows, macOSWebmail
mailxUnix-likeTUI
Microsoft EntourageMicrosoftmacOSGUI
Microsoft OutlookMicrosoftWindows, macOSGUI
Mozilla Mail & NewsgroupsMozilla FoundationGUI
Mozilla ThunderbirdMozilla FoundationCross-platformGUI
MulberryCyrus Daboo Cross-platformGUI
MuttMichael ElkinsCross-platformTUI
Netscape MessengerNetscape Communications?GUI
Netscape Messenger 9Netscape CommunicationsGUI
Nylas MailNylasmacOS, Linux, WindowsGUI
nmh / MHRAND CorporationUnix-likeCLI
Opera MailOpera SoftwareCross-platformGUI
Outlook ExpressMicrosoftWindowsGUI
Pegasus MailDavid HarrisWindowsGUI
PineUniversity of WashingtonCross-platformTUI
PocomailPoco SystemsWindowsGUI
RoundCubeThe RoundCube TeamCross-platformWebmail
SeaMonkey Mail & NewsgroupsSeaMonkey CouncilCross-platformGUI
SparkReaddlemacOSGUI
SpicebirdSynovelWindows, Linux, BSDGUI
SquirrelMailThe SquirrelMail Project TeamCross-platformWebmail
SylpheedHiroyuki YamamotoCross-platformGUI
The Bat!RitLabsWindowsGUI
TrojitáKDECross-platformGUI
TurnpikeThus PLC WindowsGUI
Windows Live MailMicrosoftWindowsGUI
Windows MailMicrosoftWindowsGUI
YAMYAM Open Source Team and contributing authorsAmigaOSGUI
Zimbra DesktopZimbraCross-platformGUI
ClientAuthor/DeveloperOperating systemSoftware licenseUser interface

Release history

A brief digest of the release histories.
ClientFirst public DateFirst public VersionFirst stable DateFirst stable VersionLatest stable release
Alpine2006-110.82007 December1.002017-03-17,
Apple Mail?????
Becky! Internet Mail199612017-08-29,
Citadel198719881.002017-01-15,
Claws Mail2001-050.4.672005-011.0.02017-08-29,
Cone2003-050.502003-050.502016-08-03,
Courier2004-063.5discontinueddiscontinued2004-06,
Elm19861987-0322005-08-18,
eM Client2007-111.02007-111.02020-06-27,
EmailTray2010-102.02011-033.112012-07-02,
Eudora198819882006-10-11,
Eureka Email2002-111.02002-111.02005-03-01,
Evolution2000-05-110.02001-12-031.02017-09-13,
Forté Agent2014-10-20,
Geary0.10.12017-10-02,
Gnus19871988-02-012.02015-04-06,
GroupWise19861.02014-04-02,
Hiri2014-020.42016-061.02017-06-10,
i.Scribe / InScribe19991.002014-08-04,
IBM Lotus Notes19891.019891.02013-03-14,
IMP19981.02016-09-06,
K-9 Mail2018-09-02
KMail1998-10Alpha1999-021.0.172014-11-11,
Mailbird2013-04-01Public Beta2018-12-19,
Mailpile2011-112019-09-04
Microsoft Entourage2013-03-12,
Microsoft Office Outlook1997971997972019-05-09,
Mozilla Thunderbird2003-07-280.12004-12-071.02019-03-25,
Mulberry1996-09-201.01996-09-201.02007-02-21,
Mutt19952017-09-02,
Netscape Messenger2007-08-17,
Netscape Messenger 92007-11-159.0a1discontinueddiscontinued2007-11-15
nmh / MH19792012-06-11,
Opera Mail1996-092.1b11996-122.12016-02-16,
Outlook Express19963.02004-08-25,
Pegasus Mail199019902018-06-07,
Pine1992-01-152.001992-01-152.002005-09-28,
Pocomail19992009-04-06,
RoundCube20060.1-rc12014-04-071.0.02017-04-28, 1.2.5
SeaMonkey Mail & Newsgroups2005-09-151.0a2006-01-301.02017-07-31,
SquirrelMail1999-120.12001-011.02011-07-12,
Sylpheed2000-010.1.02004-121.0.02017-06-29,
The Bat!1997-031.0 Beta1998-031.00 Build 13102018-03-23,
Trojitá2009-080.12012-120.3.902016-06-15,
Turnpike1996 1.01996 1.02006-05-23,
Windows Live Mail2007-11-06122007-11-06122014-11-04,
Windows Mail2007-01-01,
YAM19951.019951.02014-04-18,
Zimbra2005-11Beta2006-033.52014-12-15,

Operating system support

The operating systems on which the clients can run natively.

Protocol support

Communication and access protocol support

What email and related protocols and standards are supported by each client.
ClientPOP3
fetch all messages		POP3
selected by filter		POP3
selected by user		IMAP4
SMTP
NNTP
LDAP v2
LDAP v3
EWSIPv6MAPI
Alpine
Apple Mail
Becky! Internet Mail
Citadel
Claws Mail
Cone
Courier
Elm
eM Client
EmailTray
Eureka Email
Evolutionplug-inplug-in
Gnus
GroupWise
Hiri
i.Scribe / InScribe
IBM Notes
KMail
Mailbird
Mailpile
Microsoft Entourage
Microsoft Entourage 2008, Web Services Edition
Microsoft Office Outlook
Mozilla Mail & Newsgroups
Mozilla Thunderbirdextensible
Mulberry
MuttNo No
Netscape Messenger
Netscape Messenger 9
nmh / MH
Opera Mail
Outlook Express
Pegasus Mail
Pine
Pocomail
RoundCube
SeaMonkey Mail & Newsgroups
Spicebird
SquirrelMail
Sylpheed
The Bat!
Trojitá
Turnpike
Windows Live Mail
Windows Mail
YAM
Zimbra
ClientPOP3
fetch all messages		POP3
selected by filter		POP3
selected by user		IMAP4SMTPNNTPLDAP v2LDAP v3EWSIPv6MAPI

Integration protocol support

ClientIMSP
ACAP
RSS 0.91 FeedsRSS 1.0 FeedsRSS 2.0 FeedsATOM FeedsiCalendarMAPI/RPCCalDAVCardDAV
Alpine
Apple Mail
Becky! Internet Mail
Citadel
Claws Mail
Cone
Courier
Elm
eM Client
EmailTray
Eudora
Eureka Email
Evolution
Gnus
GroupWise
Hiri
i.Scribe / InScribe
IBM Lotus Notes
KMail
Mailpile
Microsoft Entourage
Microsoft Office Outlook
Mozilla Mail & Newsgroups
Mozilla Thunderbird
Mulberry
Mutt
Netscape Messenger
Netscape Messenger 9
nmh / MH
Opera Mail
Outlook Express
Pegasus Mail
Pine
Pocomail
SeaMonkey Mail & Newsgroups
Spicebird
SquirrelMail
Sylpheed
The Bat!
Trojitá
Turnpike
Windows Live Mail
Windows Mail
YAM
Zimbra
ClientIMSPACAPRSS 0.91 FeedsRSS 1.0 FeedsRSS 2.0 FeedsATOM FeedsiCalendarMAPI/RPCCalDAVCardDAV

Authentication support

SSL and TLS support

Features

Information on what features each of the clients support.

General features

For all of these clients, the concept of "HTML support" does not mean that they can process the full range of HTML that a web browser can handle. Almost all email readers limit HTML features, either for security reasons, or because of the nature of the interface. CSS and JavaScript can be especially problematic.

Messages features

Database, folders and customization

Templates, scripts and programming languages

Internationalization

supports Email Address Internationalization.
As of October 2016, email clients supporting SMTPUTF8 included Outlook 2016, mail for iOS, and mail for Android.