Comparison of mail servers

This is a comparison of mail servers: mail transfer agents, mail delivery agents, and other computer software which provide e-mail services.

Feature comparison

Mail server	Server OS support			Features								Storage			License
	Linux/Unix	Windows	Mac OS X	SMTP	POP3	IMAP	SMTP over TLS	POP over TLS	NNTP	SSL	Webmail	Database	Filesystem	Other
Alt-N Technologies' MDaemon Email Server	No	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Proprietary
Apache James	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Open Source/ASLv2
Axigen	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	No	Yes	Proprietary
Courier Mail Server	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	No	Open Source
Cyrus IMAP	Yes	?	Yes	No	Yes	Yes	No	Yes	No	Yes	No	Yes (indexes)	Yes	Yes	Open Source/BSD
Dovecot	Yes	No	Yes	No	Yes	Yes	No	Yes	No	Yes	No	No	Yes	No	Open Source/Mixed: MIT and LGPL 2.1
Emailarchitect Email Server	No	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Proprietary
Eudora Internet Mail Server	No	No	Yes	Yes	Yes	Yes	No	No	No	No	No	No	No	Yes	Proprietary
Exim	Yes	via Cygwin	Yes	Yes	No	No	Yes	No	?	Yes	No	Yes	Yes	No	Open Source/GPL
GroupWise	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	No	No	Proprietary
hMailServer	No	Yes	No	Yes	Yes	Yes	V 5.0	V 5.0	No	V 5.0	Yes	Yes	No	No	GNU GPL (V5.0 Proprietary)
IBM Lotus Domino	Yes	Yes	?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	Proprietary
IceWarp Server	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Proprietary
Ipswitch IMail Server	No	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Proprietary
Kerio MailServer	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	No	Proprietary
Mail Enable	No	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Proprietary
Mailtraq	No	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Proprietary
Meldware Mail Server	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	No	Open source/LGPL
Mercury Mail Transport System	No	Yes	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Proprietary/freeware
Microsoft Exchange Server	No	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	ESE only	No	No	Proprietary
NetMail	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	No	No	Proprietary
Postfix	Yes	No	Yes	Yes	No	No	Yes	No	No	Yes	No	Yes	Yes	Yes	Open source/IBM Public License
qmail	Yes	No	Yes	Yes	Yes	No	No	No	?	No	No	No	Yes	No	Public domain
Qpopper	Yes	Yes	Yes	No	Yes	No	No	Yes	No	Yes	No	No	Yes	Yes	BSD-style
Sendmail	Yes	No	Yes	Yes	No	No	Yes	No	No	No	No	?	Yes	?	Open source/Sendmail License
SparkEngine	Yes	Yes	Yes	Yes	No	No	Yes	No	No	Yes	No	Yes	Yes	Yes	Proprietary
Sun Java System Messaging Server	Yes	No	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	No	Proprietary
SurgeMail	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Proprietary
UW IMAP	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Yes	WebPine	No	Yes	No	Open Source/Apache license
WinGate	No	Yes	No	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	No	Yes	No	Proprietary
Zarafa	Yes	No	No	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	No	Proprietary
Zimbra	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	No	Open Source/Proprietary
Mail server	Linux/Unix	Windows	Mac OS X	SMTP	POP3	IMAP	SMTP over TLS	POP over TLS	NNTP	SSL	Webmail	Database	Filesystem	Other	License
	Server OS support			Features								Storage

Authentication

Mail server	Login			Authentication
	SMTP AUTH	POP before SMTP	APOP	Filesystem	Database	LDAP	Other
Alt-N Technologies' MDaemon Email Server	Yes	Yes	Yes	No	Yes	?	Active Directory, PLAIN, CRAM-MD5, LOGIN
Apache James	Yes	?	?	?	Yes	Yes	?
Axigen	Yes	No	Yes	No	No	Yes	GSSAPI, CRAM-MD5, DIGEST-MD5, APOP, CLRTXT, LOGIN, PLAIN, LDAP, Internal
Courier Mail Server	Yes	Yes	Yes	Yes	Yes	Yes	Pluggable Authentication Modules, userdb, CRAM, LDAP, MySQL, vchkpw/vpopmail, PostgreSQL(beta)
Eudora Internet Mail Server	Yes	No	Yes	Yes	No	No	CRAM-MD5, DIGEST-MD5, PLAIN, LOGIN
Exim	Yes	?	Yes	Yes	Yes	Yes	Cyrus SASL, Dovecot SASL, CRAM-MD5, PLAIN, LOGIN, SPA
GroupWise	Yes	Yes	Yes	Yes	Yes	Yes	eDirectory, Any LDAPv3-compliant source
IceWarp Server	Yes	Yes	Yes	Yes	Yes	Yes	PLAIN, CRAM-MD5, DIGEST-MD5, NT Domain, Active Directory, any LDAP-compatible source
Ipswitch IMail Server	Yes	No	Yes	Yes	Yes	Yes	Active Directory, Windows authentication, CRAM-MD5, PLAIN, LOGIN
Kerio MailServer	Yes	Yes	Yes	Yes	No	Yes	Active Directory, Apple Open Directory, ActiveSync, Pluggable Authentication Modules
Mailtraq	Yes	Yes	Yes	Yes	Yes	Yes	NT Domain, Active Directory, Local Directory
Meldware Mail Server	Yes	No	Yes	Yes	Yes	Yes	?
Mercury Mail Transport System	Yes	Yes	Yes	Yes	No	?	Internal, LOGIN, PLAIN, CRAM-MD5, Netware, LDAP?, partial NT Domain
Microsoft Exchange Server	Yes	?	Yes	No	No	Yes	Active Directory
NetMail	Yes	Yes	Yes	Yes	Yes	Yes	eDirectory, LDAP
Postfix	Yes	No	No	Yes	Yes	Yes	?
SurgeMail	Yes	?	?	Yes	Yes	Yes	?
WinGate	Yes	Yes	Yes	Yes	Yes	No	NT Domain, Active Directory, CRAM-MD5, SASL PLAIN, SASL LOGIN
Zarafa	Yes	Yes	?	Yes	Yes	Yes	Internal, Active Directory, any LDAP-compatible source, Unix
Zimbra	Yes	No	Yes	Yes	Yes	Yes	Internal, LDAP, Open LDAP, Active Directory

Antispam Features

Mail Server	DNSBL	SURBL	Spamtraps	Greylisting	SPF	Tarpit	Bayesian filters	Regular expressions	Embedded Antivirus
Alt-N Technologies' MDaemon Email Server	?	?	?	Yes	?	?	?	?	?
Apache James	?	?	?	?	?	?	?	?	?
Axigen	?	?	?	?	?	?	?	?	?
Courier Mail Server	?	?	?	?	?	?	?	?	?
Cyrus IMAP	?	?	?	?	?	?	?	?	?
Dovecot	?	?	?	?	?	?	?	?	?
Emailarchitect Email Server	?	?	?	?	?	?	?	?	?
Eudora Internet Mail Server	?	?	?	Yes	?	?	?	?	?
Exim	?	?	?	Yes	?	?	?	?	?
GroupWise	?	?	?	?	?	?	?	?	?
hMailServer	Yes	Yes	No	Yes	Yes	No	No	Yes	Yes ClamAV
IBM Lotus Domino	?	?	?	?	?	?	?	?	?
IceWarp Server	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes Avast
Ipswitch IMail Server	Yes	Yes	No	No	Yes	No	Yes	Yes	Yes Symantec
Kerio MailServer	?	?	?	?	?	?	?	?	?
Mail Enable	?	?	?	?	?	?	?	?	?
Mailtraq	?	?	?	?	?	?	?	?	?
Meldware Mail Server	?	?	?	?	?	?	?	?	?
Mercury Mail Transport System	?	?	?	?	?	?	?	?	?
Microsoft Exchange Server	?	?	?	Yes	?	?	?	?	?
NetMail	?	?	?	?	?	?	?	?	?
Postfix	Yes	?	?	Yes	?	?	?	Yes	?
qmail	?	?	?	Yes	?	?	?	?	?
Sendmail	?	?	?	Yes	?	?	?	?	?
SparkEngine	?	?	?	?	?	?	?	?	?
Sun Java System Messaging Server	?	?	?	?	?	?	?	?	?
SurgeMail	?	?	?	?	?	?	?	?	?
UW IMAP	?	?	?	?	?	?	?	?	?
WinGate	?	?	?	?	?	?	?	?	?
Zarafa	?	?	?	?	?	?	?	?	?
Zimbra	Yes	?	?	?	?	?	?	?	Yes ClamAV
Mail Server	DNSBL	SURBL	Spamtraps	Greylisting	SPF	Tarpit	Bayesian filters	Regular expressions	Embedded Antivirus

See also

• List of mail servers