|
- RPMs:
|
-
Postfix:
http://web6.dialin.co.uk/~sjmudd/postfix/RPMS/i386/
-
Courier-MTA:
ftp://duke.eburg.com/pub/linux/redhat-7.x-mycontrib/i386/
- Exim:
http://www.rpmfind.net/linux/rpm2html/search.php?query=exim
-
qmail: there are not binary rpm packages, but you can get source
rpm packages from: http://www.qmail.org/rpms/var-qmail/
|
|
-
Licence:
|
-
qmail: "you cannot redistributed modified qmail
source code packages"
|
|
-
Quota support:
|
-
Postfix: Using virtual delivery agent, you can use
virtual_mailbox_size that it is something similar to quotas, but
you cannot use it with Maildir mailboxes. You can also try the
following patches:
-
Patch provided by Keith Stevenson
-
Patch Provided by alcove-labs
or look for new patches in
Postfix addons
page.
These patches have never been included in the
original distribution because the author Wietse Venema doesn't
want to integrate functionnalities that does not deal with smtp
server directly.
- Courier-MTA: "Courier can
manually enforce a quota for mail accounts that use maildirs.
This quota enforcement is implemented entirely in software, and
is available only when maildirs++ are used. This quota
implementation will also work with virtual accounts. At this
time, maildir quota support is available only with userdb and
LDAP authentication back-ends. Since
version 0.34.1 also maildir quota support is implemented for a
MySQL back-end ", more
info: http://www.inter7.com/courierimap/README.maildirquota.html
, http://www.courier-mta.org/maildirquota.html
-
qmail: since qmail normally delivers to a mailbox in the user's
directory, normal Unix filesystem quotas can be used to restrict
the size of mailboxes. For single-UID applications, there are
numerous patches and add-ons listed on http://www.qmail.org,
including
http://www.pgregg.com/projects/qmail/mailquotacheck/index.php and
http://www.mrjesus.org/patches/qmail-local-quota.patch
|
|
-
Security
|
-
Both Qmail and Postfix claim to be safe MTA's.
Here you can
find some old security problems:
- Exim: Exploit
local compromise root account, Date: July 21, 1997
-
qmail: QMail
RCPT Denial of Service vulnerability due to memory
exhaustion Date: 1997-6-11 v 1.03, due
to improper configuration, not an actual bug, but anyway it was
never fixed
- Postfix: Memory
exhaustion attack vulnerability Date: 14/10/2001
|
|
-
Maturity/status:
|
-
qmail: " Seems than Dan
Bernstain (author) has not updated qmail recently (since ...)
anyway he claims to be
working on a new release since 10 Apr 2001"
|
|
-
SMTP-Auth:
|
-
Introduction: This is an extension to the SMTP protocol,
described inRFC
2554, which allows a client SMTP host to authenticate itself
to a server. By this means a server might, for example, recognize
clients that are permitted to use it as a relay. SMTP
authentication is not of relevance to the transfer of mail
between servers that have no managerial connection with each
other.
Very
briefly, the way SMTP authentication works is as follows:
The
server advertises a number of authentication mechanisms.
The
client issues an AUTH command, naming a specific mechanism. The
command may, optionally, contain some authentication data.
The
server may issue one or more challenges, to which the client must
send appropriate responses. In the simple authentication
mechanisms, the challenges are just prompts for user names and
passwords. The server does not have to issue any challenges -- in
some mechanisms the relevant data may all be transmitted with the
AUTH command.
The server either accepts or denies
authentication.
If you are setting up a client, and want to
know which authentication mechanisms the server supports, you can
use Telnet to connect to port 25 (the SMTP port) on the server,
and issue an EHLO command. The response to this includes the list
of supported mechanisms.
-
Postfix: different authentication methods are supported
using Cyrus SASL library
- Exim:
-
Sendmail: different authentication methods are supported
using Cyrus SASL library
- Cyrus SASL Library: is
the Simple Authentication and Security Layer, a method for adding
authentication support to connection-based protocols. Actually
support the following methods: ANONYMOUS, CRAM-MD5, KERBEROS_V4,
PLAIN, CRAM-MD5 (deprecated), GSSAPI (MIT Kerberos 5 or Heimdal
Kerberos 5), DIGEST-MD5, LOGIN(unsupported), SRP (unsupported,
may not work). For different methods supported by email clients
you can check this table: SASL
Ref Client
|
|
-
Installation:
|
-
qmail: Sometimes it is a bit
confusing due to many patches make confusing installation also
there are not binary rpm packages
availables , you have to compile from source.
|
|
- Release
|
-
Postfix was released 22/01/1999 for the first time
|
|
- IPv6
|
-
Posffix does not implement native ipv6 support, but i think they
are working on it ¿am i right?
- Exim:
http://www.exim.org/exim-html-3.20/doc/html/spec_1.html#SEC6
-
Courier-MTA: experimental
|
|
- Pop
Server:
|
-
Courier-mta: SSL version of pop service is also included
|
|
-
Imap Server:
|
-
Courier-mta: SSL version of imap service is also included, added
experimental support for IMAP quota extension
|
|
-
IPv6:
|
-
Courier-mta: experimental
|
|
-
Ldap:
|
-
Courier-mta: Supports for OpenLDAP 2.x, LDAP-based mail
routing is also supported.
- qmail: you can find this
patch in http://www.nrg4u.com
(Supports OpenLDAP 1.2.X and Mozilla Directory SDK.
- Exim
|
|
-
MySQL:
|
-
Postfix: also have support for MYSQL connections over
UNIX-domain
- Courier-MTA: actually v.0.38 there is no
mysql-based alias support.
|
|
-
PostgreSQL:
|
- Courier-MTA: added experimental
support since version 0.36
|
|
-
Mailbox Format:
|
-
Maildir: the first implementation and definition of
Maildirs were in qmail mail server. Since then independent
developers added additional features on top of if, such a folders
an volutary mail quotas.
- Mbox Benchmarking: Sam
Varshavchik
- Maildir++: this
extension to the maildir format allows a "voluntary"
maildir quota implementation that does not rely on
filesystem-based quotas, more info:
http://www.inter7.com/courierimap/README.maildirquota.html
|
|
-
StartTLS:
|
-
Exim
|
|
-
Configurable DSN Extensions:
|
What
is "Configurable DSN Extension"?
When a message
fails to get delivered, or remains on the queue for more than a
configured amount of time, Mail server sends a message to the
original sender reporting the status of the delivering. Some MTA
provides the avility to configure the text of these messages.
-
Courier-MTA: "Courier offers complete support for the DSN
SMTP extensions, as specified by RFC 1894". Example
-
RFC
Documentation
|
|
-
ESMTP over SSL/TLS:
|
-
Courier-MTA: "Courier-MTA ESMTP client has the ability to
verify that X.509 certificates are signed by a trusted
certificate authority when sending mail with ESMTP over SSL/TLS.
This is disabled by default."
|
|
-
Documentation:
|
-
Exim: "Exim
the mail transport Agent" written by Philip Hazel
-
Qmail: "Life with
qmail" written by Dave Sill
|
|
-
Web-based Administration:
|
-
Courier-mta: It requires a CGI-capable web server
- Postix:
using webmin
-
qmail: using webmin
|
|
-
Verbosity logging options:
|
- Courier-mta: no verbosity logging options.
- qmail: by
default logs everything, the loggin utilities used with most
qmail installations -- from the daemontools quite -- allow the
user to filter the log stream as they desire.
- Postfix: the
Postfix SMTP server maintains a record of SMTP conversations for
debugginf purposes. Depending on local configuration details this
record is mailed to the postmaster whenever an SMTO session
terminates with errors.
|
|
- Log
analising utilities:
|
-
Postfix
http://jimsun.linxnet.com/postfix_contrib.html
MRTG for Postfix
Postfix
Addons section
-
Sendmail:
http://www.reedmedia.net/software/sendmail_stats/#other-reports
-
qmail:
qmail
analog: the standard log analyzer, developed by the author of
qmail
http://www.enderunix.org/isoqlog/maillog-stable15/
(Very Good)
- Exim:
The Exim Monitor is an optional
extra; it displays information about Exim's processing in an X
window, and an administrator can perform a number of control
actions from the window interface.
There are a set of tools
for summarising the queue, determining what each exim process is
currently doing, examining the deliveries hints databases, and
summarising the log files into a concise report on activity.
|
|
- Other mail server
information pages:
|
-
Tucows
Email Servers
- Cameron
Laird's personal notes on mail transfer agents
-
http://www.sendmail.org/~ca/email/mel/Links.html
|
|
|
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