* Introduced Postscreen
cheaper, earlier and simpler blocking of zombies/spambots.
From http://postfix.cs.utah.edu/POSTSCREEN_README.html :
As a first layer, postscreen(8) blocks connections from zombies and other spambots that are responsible for about 90% of all spam. It is implemented as a single process to make this defense as cheap as possible.
Things we need to consider:
- Do we need a whitelist/backlist file? (http://postfix.cs.utah.edu/postconf.5.html#postscreen_access_list)
- Via introducing an optional config/postfix-access.cidr
- The only permanent whitelisting I could imagine are monitoring services(which might (still?) behave weird/hastely) or blacklisting backup servers(since no traffic should be coming from them anyway)
- Do we need deep inspections? They are desireable, but these tests are expensive: a good client must disconnect after it passes the test, before it can talk to a real Postfix SMTP server. Considered tests are:
- postscreen_bare_newline_enable (http://postfix.cs.utah.edu/postconf.5.html#postscreen_bare_newline_action)
- postscreen_non_smtp_command_enable (http://postfix.cs.utah.edu/postconf.5.html#postscreen_non_smtp_command_action)
- postscreen_pipelining_enable (http://postfix.cs.utah.edu/postconf.5.html#postscreen_pipelining_action)
- Do we need to make the blacklisting via dnsblocking configurable? It's currently set and weighted as follows, where a score of 3 results in blocking, a score of -1 results in whitelisting:
(*: adds the specified weight to the SMTP client's DNSBL score. Specify a negative number for whitelisting.)
(http://postfix.cs.utah.edu/postconf.5.html#postscreen_dnsbl_sites)
- zen.spamhaus.org*3
- bl.mailspike.net
- b.barracudacentral.org*2
- bl.spameatingmonkey.net
- bl.spamcop.net
- dnsbl.sorbs.net
- psbl.surriel.com
- list.dnswl.org=127.0.[0..255].0*-2
- list.dnswl.org=127.0.[0..255].1*-3
- list.dnswl.org=127.0.[0..255].[2..3]*-4
- What to do when blacklisting? I currently set it to drop. We could
- ignore: Ignore the failure of this test. Allow other tests to complete. Repeat this test the next time the client connects. This option is useful for testing and collecting statistics without blocking mail.
- enforce: Allow other tests to complete. Reject attempts to deliver mail with a 550 SMTP reply, and log the helo/sender/recipient information. Repeat this test the next time the client connects.
- drop: Drop the connection immediately with a 521 SMTP reply. Repeat this test the next time the client connects.
In the end I think we could drop postgrey support. Postscreen replaces postgrey in its entirety, while being more selective and not delaying mail. Especially if we consider using the deep inspection options of postscreen.
Hope that wasn't too much to read! ;)
* main.cf got misformatted..
Don't know how, should be ok now.
* fixed malformatted main.cf & repaired master.cf
* reenabled rbl stuff.. It's cached, therefore doesn't hurt
* fixed tests
* added tests, repaired tests, added info, introduced new Variable POSTSCREEN_ACTION, fixes
* install dovecot from backports
* dovecot 2.2.33 has a slightly different TLS-configuration than 2.2.27
* want to have both images a the same time
* make use of the /etc/dovecot/ssl as mkcert.sh (2.2.33) is using that folder for certs.
* fail2ban handling integrated in setup.sh
- calling \"./setup debug fail2ban\" lists all iptable chains whith blocked IPs (like: Banned in dovecot: 91.200.12.164
Banned in postfix-sasl: 91.200.12.164)
- calling \"./setup debug fail2ban unban xxx.xxx.xxx.xxx [yyy.yyy.yyy.yyy ...]\" unbans/removes those IPs from all jails.
- calling \"./setup debug fail2ban unban\" (without an IP) gives an descriptive error: (You need to specify an IP address. Run "./setup.sh debug fail2ban" to get a list of banned IP addresses.)
* disable_vrfy_command: (#798)
Prevents Spammers from collecting existing mail-addresses by probing the mailserver for them.
* Added support for Dovecot and Postfix LDAP TLS (#800)
* Allow setup of LDAP STARTTLS for Dovecot and Postfix
* Added tests for TLS config override
* Add missing Postfix TLS options
* Added missing new line at the end of the file
* Added STARTTLS tests for Postfix config
* tests added
and made the script output look more shiny.
* setup.sh enhancements
* Allow setup of LDAP STARTTLS for Dovecot and Postfix
* Added tests for TLS config override
* Add missing Postfix TLS options
* Added missing new line at the end of the file
* Added STARTTLS tests for Postfix config
* Switch to stretch-slim as base image.
- first step correct the testdata, as newer packages are more strict
about the mail-structure.
* Switch to stretch-slim: correcting the test-environment and the build
- add missing build-step to make
- clean the userdb aswell
- use timeout of netcat, as postgrey would not close the connection
- there is 2 extra mail-logs -> assert_output 5
- cosmetic: use "" instead of ''
* Switch to stretch-slim:
new image:
- smaller size
- 0 CVEs compared to 11 CVEs in ubuntu 16.04 Image
better backport situation
- postfix 3.1.6 vs 3.1.0
- fail2ban 0.9.6 vs 0.9.3
...
changes needed because of stretch-slim:
- add missing gnupg and iproute2 package
- remove non-free rar, unrar-free should do
- rsyslog does not add syslog user and has different conf-structure
- pyzor command discover was deprecated and is missing in the new
stretch package
- dovecot does not know SSLv2 anymore. removed because of warnings in
log
- iptables does not know imap3, IMAP working group chose imap2 in favor
of imap3
* Switch to debian stretch slim:
SSLv2 seems to be a not known protocol anymore - good!
* switch to debian stretch slim:
make this test more stable. there might be more than only one mail.log
(mail.info, mail.warn, ...)
* switch to debian stretc slim:
new openssl 1.1.0 needs stronger ciphers, removed some weekers ones.
Please, look through the new list of cipher! this needs to be done in
another commit for all other SSL/TLS-Endpoints aswell.
* Switch to debian stretch slim:
let our server pre-empt the cipher list.
Did a read through, wwwDOTpostfixDOTorg/FORWARD_SECRECY_READMEDOThtml
and
wwwDOTpostfixDOTorg/TLS_READMEDOThtml
* Switch to debian stretch slim: lets give this openssl-based test a new and independent but identical container. many other test on the main 'mail' container might interfere here.
* Switch to debian stretch slim: remove unused lines
* fix for issue #747 (NOT TESTED YET)
Need to test this. Dont merge it yet.
* Small Cleanup and bug fixes Not done Yet!
Not done yet. Dont merge. See comment in issue #747
* Add --ignore-missing. Now is fixed.
* Enable user definable fetchmail poll times
* create new ENV variable FETCHMAIL_POLL in target/start-mailserver.sh
* change --daemon setting in supervisor-app.conf to use ENV var
* Put FETCHMAIL_POLL env variable in Dockerfile to handle case where
user does not specify it in their docker-compose.yml
opendmarc checks fail for mail sent over (SMTP AUTH) submission
ports. Adding this directive skips checks for those emails, and
clears the logs of related errors.
See https://github.com/tomav/docker-mailserver/issues/703
