From b7c15c31519dc44c1f691e0466badd556ffe9423 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:18:56 +0200 Subject: Adding upstream version 3.7.10. Signed-off-by: Daniel Baumann --- html/LINUX_README.html | 119 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 html/LINUX_README.html (limited to 'html/LINUX_README.html') diff --git a/html/LINUX_README.html b/html/LINUX_README.html new file mode 100644 index 0000000..0d5b0ee --- /dev/null +++ b/html/LINUX_README.html @@ -0,0 +1,119 @@ + + + + + + +Postfix and Linux + + + + + + + +

Postfix and Linux

+ +
+ +

Host lookup issues

+ +

By default Linux /etc/hosts lookups do not support multiple IP +addresses per hostname. This causes warnings from the Postfix SMTP +server that "hostname XXX does not resolve to address YYY", and is +especially a problem with hosts that have both IPv4 and IPv6 +addresses. To fix this, turn on support for multiple IP addresses:

+ +
+
+/etc/host.conf:
+    ...
+    # We have machines with multiple IP addresses.
+    multi on
+    ...
+
+
+ +

Alternatively, specify the RESOLV_MULTI environment variable +in main.cf:

+ +
+
+/etc/postfix/main.cf:
+    import_environment = MAIL_CONFIG MAIL_DEBUG MAIL_LOGTAG TZ XAUTHORITY DISPLAY LANG=C RESOLV_MULTI=on
+
+
+ +

Berkeley DB issues

+ +

If you can't compile Postfix because the file "db.h" +isn't found, then you MUST install the Berkeley DB development +package (name: db???-devel-???) that matches your system library. +You can find out what is installed with the rpm command. For example: +

+ +
+
+$ rpm -qf /usr/lib/libdb.so
+db4-4.3.29-2
+
+
+ +

This means that you need to install db4-devel-4.3.29-2 (on +some systems, specify "rpm -qf /lib/libdb.so" instead).

+ +

DO NOT download some Berkeley DB version from the network. +Every Postfix program will dump core when it is built with a different +Berkeley DB version than the version that is used by the system +library routines. See the DB_README file for further information. +

+ +

Procmail issues

+ +

On RedHat Linux 7.1 and later procmail no longer has +permission +to write to the mail spool directory. Workaround:

+ +
+
+# chmod 1777 /var/spool/mail
+
+
+ +

Logging in a container

+ +

When running Postfix inside a container, you can use stdout +logging as described in MAILLOG_README. Alternatives: run syslogd +inside the container, or mount the host's syslog socket inside the +container.

+ +

Syslogd performance

+ +

LINUX syslogd uses synchronous writes by default. Because +of this, syslogd can actually use more system resources than +Postfix. To avoid such badness, disable synchronous mail logfile +writes by editing /etc/syslog.conf and by prepending a - to the +logfile name:

+ +
+
+/etc/syslog.conf:
+    mail.*                          -/var/log/mail.log
+
+
+ +

Send a "kill -HUP" to the syslogd to make the +change effective.

+ +

Other logging performance issues

+ +

LINUX systemd intercepts all logging and enforces its +own rate limits before handing off requests to a backend such as +rsyslogd or syslog-ng. On a busy mail server this can +result in information loss. As a workaround, you can use Postfix's +built-in logging as described in MAILLOG_README.

+ + + + -- cgit v1.2.3