Comparison of email clients explained

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

General

Basic general information about the clients: creator/company, O/S, license, and interface.

Client	Author/Developer	Operating system	Software license	User Interface
	Alpine	University of Washington	Cross-platform		TUI
	Apple Mail	Apple	macOS, iOS, watchOS		GUI (Cocoa)
	Balsa	Stuart Parmenter	Linux		GUI (GTK3)
	Becky! Internet Mail	Rimarts	Windows		GUI
	BlitzMail	Dartmouth College			GUI
	Canary Mail	Cartasec Pte. Ltd.	Cross-platform		GUI
	Citadel	citadel.org	Unix-like		Webmail
	Claws Mail	the Claws Mail team	Cross-platform		GUI (GTK2)
	Courier (formerly Calypso)	Micro Computer Systems, Inc., continued by Rose City Software	Windows		GUI
	Elm	Dave Taylor, Sydney Weinstein, Bill Pemberton, Michael Elkins, Kari Hurtta	Unix-like	^[1]	TUI
	eM Client	eM Client Inc.	Windows, macOS, Android, iOS		GUI
	EmailTray	Internet Promotion Agency S.A.	Windows, Android		GUI
	Eudora OSE	Qualcomm	Windows, macOS		GUI
	Evolution	The GNOME Project	Unix-like		GUI (GTK)
	FirstClass	Open Text			GUI
	Forté Agent	Mark Sidell	Windows		GUI
	Geary	The GNOME Project (formerly Yorba Foundation)	Unix-like		GUI (GTK)
	GNUMail	Ludovic Marcotte and others	Unix-like, macOS		GUI
	Gnus	Gnus team	Cross-platform		TUI and GUI
	GroupWise	Micro Focus (formerly Novell)	Cross-platform		GUI
	Hiri	Hiri	Cross-platform		GUI
	i.Scribe, InScribe	Memecode	Windows, macOS, Linux		GUI
	HCL Notes (formerly IBM Notes and IBM Lotus Notes)	HCL Technologies (formerly IBM and Lotus Software), HCL Technologies	Windows, macOS, Linux		GUI (Notes), Web (Verse, iNotes) and Mobile (Traveler)
	IMP	Horde LLC	Cross-platform		Webmail
	K-9 Mail	K-9 Dog Walkers: cketti, et al.	Android		GUI
	KMail	KDE	Cross-platform		GUI (Qt)
	Mail (Windows)	Microsoft	Windows		GUI
	Mailbird	Mailbird	Windows		GUI
	Mailpile	Mailpile	Windows, macOS, Linux		Webmail
	mailx		Unix-like		TUI
	Microsoft Entourage	Microsoft	macOS		GUI
	Microsoft Outlook	Microsoft	Windows, macOS		GUI
	Mozilla Mail & Newsgroups	Mozilla Foundation			GUI (XUL)
	Mozilla Thunderbird	Mozilla Foundation	Cross-platform		GUI (XUL)
	Mulberry	Cyrus Daboo (formerly Cyrusoft International, Inc./ISAMET)	Cross-platform		GUI
	Mutt	Michael Elkins	Cross-platform		TUI (ncurses)
	Netscape Messenger	Netscape Communications			GUI
	Netscape Messenger 9	Netscape Communications			GUI
	Nylas Mail	Nylas	Windows, macOS, Linux		GUI
	nmh / MH	RAND Corporation	Unix-like		CLI
	Opera Mail	Opera Software	Cross-platform		GUI
	Outlook Express	Microsoft	Windows		GUI
	Pegasus Mail	David Harris	Windows		GUI
	Pine	University of Washington	Cross-platform	^[2]	TUI
	Pocomail	Poco Systems	Windows		GUI
	RoundCube	The RoundCube Team	Cross-platform		Webmail
	Samsung Email	Samsung Electronics	Samsung, Android 8+	Proprietary	GUI
	SeaMonkey Mail & Newsgroups	SeaMonkey Council	Cross-platform		GUI (XUL)
	Spark	Readdle	macOS		GUI
	SquirrelMail	The SquirrelMail Project Team	Cross-platform		Webmail
	Superhuman	Rahul Vohra	Cross-platform		Webmail
	Sylpheed	Hiroyuki Yamamoto	Cross-platform		GUI (GTK2)
	The Bat!	RitLabs	Windows		GUI
	Trojitá	KDE	Cross-platform		GUI (Qt)
	Turnpike	Thus PLC (Demon Internet)	Windows		GUI
	Vivaldi	Vivaldi Technologies AS	Cross-platform		GUI (Chrome)
	Windows Live Mail	Microsoft	Windows		GUI
	Windows Mail (Vista)	Microsoft	Windows		GUI
	YAM	YAM Open Source Team and contributing authors	AmigaOS		GUI
	Zimbra Desktop	Zimbra	Cross-platform		GUI
Client	Author/Developer	Operating system	Software license	User interface

Release history

A brief digest of the release histories.

Client	First public Date	First public Version	First stable Date	First stable Version	data-sort-type="text"	Latest stable release
	Alpine	2006-11	0.8	2007 December	1.00
	Apple Mail	2001-03-24	?	?	?
	Becky! Internet Mail	1996	1
	Canary Mail	15 June 2017	1.0	15 June 2017	1.0	4.01 (5th June, 2023)
	Citadel	1987		1988	1.00
	Claws Mail	2001-05	0.4.67	2005-01	1.0.0
	Courier	2004-06	3.5	discontinued	discontinued
	Elm	1986		1987-03	2
	eM Client	2007-11	1.0	2007-11	1.0
	EmailTray	2010-10	2.0	2011-03	3.11
	Eudora	1988^[3]		1988
	Evolution	2000-05-11	0.0	2001-12-03	1.0
	Forté Agent
	Geary	2012	0.1	2012	0.1
	Gnus	1987^[4]		1988-02-01	2.0	2015-04-06
	GroupWise			1986	1.0
	Hiri	2014-02	0.4	2016-06	1.0
	i.Scribe / InScribe	1999	1.00
	HCL Notes (formerly IBM Lotus Notes)	1989	1.0	1989	1.0
	IMP			1998	1.0
	K-9 Mail
	KMail	1998-10	Alpha	1999-02	1.0.17
	Mailbird	2013-04-01	Public Beta
	Mailpile	2011-11	^[5]	^[6]	^[7]
	Microsoft Entourage
	Microsoft Office Outlook	1997	97	1997	97
	Mozilla Thunderbird	2003-07-28	0.1	2004-12-07	1.0
	Mulberry	1996-09-20	1.0	1996-09-20	1.0
	Mutt	1995
	Netscape Messenger
	Netscape Messenger 9	2007-11-15	9.0a1	discontinued	discontinued	2007-11-15
	nmh / MH	1979
	Opera Mail	1996-09	2.1b1	1996-12	2.1
	Outlook Express	1996	3.0
	Pegasus Mail	1990		1990
	Pine	1992-01-15	2.00	1992-01-15	2.00
	Pocomail	1999
	RoundCube	2006	0.1-rc1	2014-04-07	1.0.0
	SeaMonkey Mail & Newsgroups	2005-09-15	1.0a	2006-01-30	1.0
	SquirrelMail	1999-12	0.1	2001-01	1.0
	Sylpheed	2000-01	0.1.0	2004-12	1.0.0
	The Bat!	1997-03	1.0 Beta	1998-03	1.00 Build 1310
	Trojitá	2009-08	0.1	2012-12	0.3.90
	Turnpike	1996 (circa)	1.0	1996 (circa)	1.0
	Vivaldi	2015-11-03	Beta 1	2022-06-09	1.0
	Windows Live Mail	2007-11-06	12	2007-11-06	12
	Windows Mail					2007-01-01
	YAM	1995	1.0	1995	1.0
	Zimbra	2005-11	Beta	2006-03	3.5

Operating system support

The operating systems on which the clients can run natively (without emulation).

Client	Microsoft Windows	macOS	Linux	BSD	Unix	DOS	Other
	Alpine
	Apple Mail
	Balsa
	Becky! Internet Mail
	Canary Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	Evolution
	Forté Agent
	Geary
	Gnus
	GroupWise
	Hiri
	i.Scribe / InScribe
	IBM Lotus Notes
	IMP
	KMail
	Mailbird
	Mailpile
	mailx
	Microsoft Entourage		(2008)
	Microsoft Office Outlook
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird
	Mulberry
	Mutt						^[8]
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express	(up to XP)
	Pegasus Mail
	Pine						(3.96)^[9]
	Pocomail
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Vivaldi
	Windows Live Mail
	Windows Mail	(Vista)
	YAM
	Zimbra
Client	Microsoft Windows	macOS	Linux	BSD	Unix	DOS	Other

Protocol support

Communication and access protocol support

What email and related protocols and standards are supported by each client.

Client	POP3 fetch all messages (RFC 1939)	POP3 selected by filter (RFC 1939)	POP3 selected by user (RFC 1939)	IMAP4 (RFC 3501)	SMTP (RFC 5321)	NNTP (RFC 3977)	LDAP v2 (RFC 4511)	LDAP v3 (RFC 4511)	EWS	IPv6 (RFC 2460)	MAPI
	Alpine
	Apple Mail
	Becky! Internet Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Evolution
	Gnus			^[10]								^[11]
	GroupWise
	Hiri
	i.Scribe / InScribe
	HCL Notes
	KMail
	Mailbird
	Mailpile
	Microsoft Entourage
	Microsoft Entourage 2008, Web Services Edition
	Microsoft Office Outlook
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird								^[12]	extensible^[13]
	Mulberry
	Mutt		No (possible with POP3 browser)	No (possible with POP3 browser)			(slrn looks alike)	(resolve real names through NSS)
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express
	Pegasus Mail
	Pine
	Pocomail
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Vivaldi
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra
Client	POP3 fetch all messages (RFC 1939)	POP3 selected by filter (RFC 1939)	POP3 selected by user (RFC 1939)	IMAP4 (RFC 3501)	SMTP (RFC 5321)	NNTP (RFC 3977)	LDAP v2 (RFC 4511)	LDAP v3 (RFC 4511)	EWS	IPv6 (RFC 2460)	MAPI

Integration protocol support

Client	IMSP (https://datatracker.ietf.org/doc/id/draft-myers-imap-imsp-00.txt)	ACAP (RFC 2244)	RSS 0.91 Feeds	RSS 1.0 Feeds	RSS 2.0 Feeds	ATOM Feeds	iCalendar (RFC 5545)	MAPI/RPC	CalDAV (RFC 4791)	CardDAV (RFC 6352)
	Alpine
	Apple Mail
	Becky! Internet Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	Evolution
	Gnus						^[14]	^[15]
	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
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra
Client	IMSP (https://datatracker.ietf.org/doc/id/draft-myers-imap-imsp-00.txt)	ACAP (RFC 2244)	RSS 0.91 Feeds	RSS 1.0 Feeds	RSS 2.0 Feeds	ATOM Feeds	iCalendar (RFC 5545)	MAPI/RPC	CalDAV (RFC 4791)	CardDAV (RFC 6352)

Authentication support

Client	Regular		MSN (NTLM)browser login	Compuserve(RPA)	MD5 APOP	CRAM-HMAC			DIGEST-MD5	SCRAM	with hardware tokenPKCS#11	Biometric	SMTP Auth	X.509 Client certificate	OAuth
	LOGIN	PLAIN				MD5	SHA1	RIPEMD
	Alpine
	Apple Mail
	Becky! Internet Mail
	Canary Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	Evolution
	Gnus
	GroupWise
	Hiri
	i.Scribe / InScribe
	IBM Lotus Notes
	KMail
	Mailpile
	Microsoft Entourage
	Microsoft Office Outlook
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird									^[16]
	Mulberry
	Mutt
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express
	Pegasus Mail
	Pine
	Pocomail
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra
Client	Regular		MSN (NTLM)browser login	Compuserve(RPA)	MD5 APOP	CRAM-HMAC			DIGEST-MD5	SCRAM	with hardware tokenPKCS#11	Biometric	SMTP Auth	SSL/TLS Client Certificate	OAUTH
	LOGIN	PLAIN				MD5	SHA1	RIPEMD

SSL and TLS support

Client	Secure POP3		Secure IMAP4		Secure SMTP		Secure NNTP		Secure LDAP		SNI	OCSP	CRL
	SSL	TLS	SSL	TLS	SSL	TLS	SSL	TLS	SSL	TLS
	Alpine
	Apple Mail
	Becky! Internet Mail
	Canary Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	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
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá												(system)	(system)
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra
Client	Secure POP3		Secure IMAP4		Secure SMTP		Secure NNTP		Secure LDAP		SNI	OCSP	CRL
	SSL	TLS	SSL	TLS	SSL	TLS	SSL	TLS	SSL	TLS

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.

Client	email	UTF-8 support	Image blocking	Junk filtering		Phishing filtering	Thread view	Conversation view	PGP support		S/MIME support
				local	server- side				inline	PGP/MIME or OpenPGP	protocol	OCSP	CRL	certificates on tokens, smartcards support
	Alpine
	Apple Mail
	Becky! Internet Mail
	Canary Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	Evolution
	Gnus
	GroupWise
	Hiri
	i.Scribe / InScribe
	HCL Notes										(4.1.2+)		^[17]
	KMail									(with GPG)	(1.5+, with GPGME)
	Mailbird
	Mailpile
	Microsoft Entourage
	Microsoft Office Outlook								(2010+)^[18]
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird
	Mulberry
	Mutt			Yes (no support for images)										(with GPGME)
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express
	Pegasus Mail										Yes (sending is broken)
	Pine									(with Pine Privacy Guard)
	Pocomail
	RoundCube						(depends on antivirus)
	SeaMonkey Mail & Newsgroups
	SquirrelMail						(depends on antivirus)
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra						(depends on antivirus)
Client	HTML email	UTF-8 support	Image blocking	Junk filtering		Phishing filtering	Thread view	Conversation view	PGP support		S/MIME support
				local	server- side				inline	PGP/MIME or OpenPGP	protocol	OCSP	CRL	certificates on tokens, smartcards support

Messages features

Client	Label messages				Reformat received messages		Bi-directional text support	Composing messages			Native images preview					Postpone / scheduled message sending	Native documents preview
	with colors	with flag	antidelete	add note	edit headers (e.g., Subject)	forced recode		Spell checking	Signatures	Bottom-posts replies	jpeg	gif	bmp	png	others		txt	pdf	doc	xls	odt	ods	others
	Alpine
	Becky! Internet Mail
	Canary Mail
	Citadel
	Claws Mail
	Courier
	Elm
	eM Client
	EmailTray
	Eudora
	Evolution
	Gnus
	GroupWise
	Hiri
	i.Scribe / InScribe
	HCL Notes
	KMail	^[19]
	Mailbird
	Mailpile
	Microsoft Entourage
	Microsoft Office Outlook																							PowerPoint
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird					^[20]
	Mulberry
	Mutt
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express
	Pegasus Mail
	Pine
	Pocomail
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!
	Trojitá
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra
Client	Label messages				Reformat received messages		Bi-directional text support	Composing messages			Native images preview					Postpone/?scheduled message sending	Native documents preview
	with colors	with flag	antidelete	add note	edit headers (e.g., Subject)	forced recode		Spell checking	Signatures	Bottom-posts replies	jpeg	gif	bmp	png	others		txt	pdf	doc	xls	odt	ods	others

Database, folders and customization

Client	Message file format	Encrypted database	Virtual folders	Scheduled backup	New mail notification				Customizable interface	Customizable keybindings	Fragmented messages	Database search with regular expressions support	Indexed search	Search folders	IMAP
					ticker	tray icon	tooltip	sound							Search	IDLE
	Alpine	mbox, mbx, MIX, maildir (with patches), MMDF, tenex, mtx, MH, mx, news, phile
	Becky! Internet Mail	mbox
	Canary Mail
	Citadel
	Claws Mail	MH, mbox (plugin)
	Courier	Proprietary	(weak)							(layout)
	Elm
	eM Client	Proprietary (sqlite)
	EmailTray	Proprietary
	Eudora	modified mbox
	Evolution	maildir, mbox, MH
	Gnus	babyl, maildir, mbox, MMDF, news, rnews, SOUP, outlook, oe-dbx
	GroupWise	Proprietary
	Hiri	Proprietary
	IBM Notes	Proprietary	^[21]
	KMail	mbox, maildir
	Mailbird	Proprietary
	Mailpile
	Microsoft Entourage	Proprietary (Personal Storage Table)
	Microsoft Office Outlook	Proprietary (Personal Storage Table)
	Mozilla Mail & Newsgroups	mbox
	Mozilla Thunderbird	mbox, maildir												(as of 3.0)
	Mulberry
	Mutt	mbox, MMDF, MH, maildir	(with compressed folders patch^[22])	(has limit command)
	Netscape Messenger	mbox
	Netscape Messenger 9	mbox
	nmh / MH	MH
	Opera Mail	mbox, MH, Proprietary		(all folders are virtual)
	Outlook Express	Proprietary
	Pegasus Mail	Proprietary (mbox-like)															^[23]
	Pine	mbox, mbx, MIX, maildir (with patches), MMDF, tenex, mtx, MH, mx, news, phile
	Pocomail	mbox
	RoundCube	[IMAP Server]
	i.Scribe / InScribe	Proprietary (sqlite)
	SeaMonkey Mail & Newsgroups	mbox
	SquirrelMail	[IMAP Server]
	Sylpheed	MH
	The Bat!	Proprietary	Yes (AES 128 bit)(with Pro and Voyager version)										(PCRE 6.2)
	Trojitá	IMAP
	Turnpike	Proprietary
	Windows Live Mail	File System (.eml)
	Windows Mail
	YAM	mbox, maildir, oe-dbx
	Zimbra	File system
Client	Message file format	Encrypted database	Virtual folders	Scheduled backup	New mail notification				Customizable interface	Customizable keybindings	Fragmented messages	Database search with regular expressions support	Indexed search	Search folders	IMAP
					ticker	tray icon	tooltip	sound							Search	IDLE

Templates, scripts and programming languages

Client	Message templates						Message templates individual for	Support in message templates scripts, programming languages
	new	reply	forward	read confirmation	save	print		JavaScript	VBScript	PHP Scripts	Python	Regular expressions	Java	Other (specify)
	Alpine							any
	Becky! Internet Mail							any account folder
	Canary Mail
	Citadel
	Claws Mail							account folder
	Courier
	Elm
	eM Client							account
	Eudora							any
	Evolution
	Gnus
	GroupWise
	Hiri							any
	i.Scribe / InScribe							any
	IBM Notes												^[24]
	KMail							none
	Mailpile
	Microsoft Entourage
	Microsoft Office Outlook
	Mozilla Mail & Newsgroups
	Mozilla Thunderbird							profile
	Mulberry
	Mutt							any
	Netscape Messenger
	Netscape Messenger 9
	nmh / MH
	Opera Mail
	Outlook Express
	Pegasus Mail
	Pine							any
	Pocomail
	RoundCube
	SeaMonkey Mail & Newsgroups
	SquirrelMail
	Sylpheed
	The Bat!							account folder address book group contact
	Turnpike
	Windows Live Mail
	Windows Mail
	YAM
	Zimbra							any
Client	Message templates						Message templates individual for	Support in message templates scripts, programming languages
	new	reply	forward	read confirmation	save	print		JavaScript	VBScript	PHP Scripts	Python	Regular expressions	Java	Other (specify)

Internationalization

The Bat! supports Email Address Internationalization (EAI).^[25]

As of October 2016, email clients supporting SMTPUTF8 included Outlook 2016,^[26] mail for iOS, and mail for Android.

See also

• Comparison of feed aggregators
• Comparison of browser engines
• Comparison of mail servers
• Comparison of webmail providers
• List of personal information managers
• Unicode and email
• Webmail

External links

• T&B : Email : Clients (of historical interest—last updated in 1999)
• Mail User Agents for Linux Based Platforms (includes many email clients not listed in the above tables)
• Remail - research by The Collaborative User Experience group at IBM

Notes and References

1. http://www.elmme-mailer.org/NOTICE Elm Mail System GPL
2. Web site: Pine License . 2006-02-24 . https://web.archive.org/web/20180602121205/http://www.washington.edu/pine/overview/legal.html . 2018-06-02 . dead .
3. Web site: The Birth of Eudora . 2007-04-10 . https://web.archive.org/web/20021108211012/http://www.eudora.com/presskit/backgrounder.html . 2002-11-08 . dead .
4. Web site: GNUS: a NNTP based news reader for GNU Emacs (1 of 2). 2008-08-04. dead. https://web.archive.org/web/20160303190300/http://gnus.org/2.0/gnus.1. 2016-03-03.
5. https://github.com/mailpile/Mailpile/wiki/Release-Notes-201401-Alpha Alpha
6. https://www.mailpile.is/blog/2017-01-30_A_Plan_for_2017.html tbd 2017
7. https://www.mailpile.is/blog/2017-08-13_SHA2017.html 1.00 RC
8. Web site: Other Programming Projects and Downloads. 2007-04-06. https://web.archive.org/web/20070404233358/http://caddit.net/programming.php. 2007-04-04. dead.
9. Web site: [ftp://ftp.cac.washington.edu/pine/pcpine/old/PC-PINE-3.96/README PC-PINE-3.96 README]. 2007-04-06.
10. (setq gnus-select-method '(pop3 "pop.example.com"))
    (setq gnus-secondary-select-methods '((nntp "news.gnus.org")))
    After configuring Gnus for POP3, you can use the gnus-group-get-new-news command to retrieve new messages from your POP3 server.
11. Web site: w32-send-mapi.el .
12. Write to LDAP still missing after 10 years, Mozilla bug 86405
13. Add-ons include MesQuilla ExQuilla Exchange Web Services (alpha) (see also ExQuilla for Microsoft Exchange) and Provider for Microsoft Exchange
14. Web site: GNU emacs - rss .
15. via org-mode
16. Web site: 335924 - No authentication with DIGEST-MD5.
17. Web site: HCL Product Documentation.
18. Web site: Sort Your Emails by Conversation in Outlook 2010 - How-To Geek . 2011-04-12 . 2011-06-25 . https://web.archive.org/web/20110625114031/http://www.howtogeek.com/howto/17937/sort-your-emails-by-conversation-in-outlook-2010 . dead .
19. Web site: Configure KMail: Appearance Page . KDE . Documentation page . https://web.archive.org/web/20180530222937/https://docs.kde.org/trunk5/en/pim/kmail2/configure-appearance.html . May 30, 2018 . live . May 30, 2018.
20. Web site: Header Tools Lite. 8 September 2022 .
21. Web site: Find product documentation and support. IBM.
22. Web site: Compressed folders patch for Mutt.
23. Web site: Pegasus Mail & Mercury - Re: IDLE . 2014-03-11 . dead . https://web.archive.org/web/20140311181717/http://community.pmail.com/forums/post/17967.aspx . 2014-03-11 .
24. Web site: IBM Docs.
25. Web site: Starting with the version 6.0 The Bat! supports IDN (Internationalized Domain Names)).
26. Web site: International email addresses - Outlook. support.office.com. 2016-10-27. https://web.archive.org/web/20161028083946/https://support.office.com/en-US/article/International-email-addresses-303595ea-4893-4b26-9b14-2202c32fea36. 2016-10-28. dead.