Some scripts and tips for easing the maintenance of a postfix based SMTP system
Posted by jpluimers on 2021/11/24
A few scripts and tips I found Googling around.
Deleting queued messages by regular expression pattern
I have seen the below delete-from-mailq.pl script numerous time, usually without any attribution (for instance [Wayback] Postfix Flush the Mail Queue – nixCraft and [Wayback] postfix-delete.pl – Following script deletes all mail from the mailq which matches the regular expression specified as the first argument · GitHub).
The earliest version I could find was in [Wayback] ‘Re: delete messages from mailq’ – MARC by [Wayback] ‘Ralf Hildebrandt ‘ posts – MARC:
--- snip ---
#!/usr/bin/perl
$REGEXP = shift || die "no email-adress given (regexp-style, e.g. bl.*\@yahoo.com)!";
@data = qx</usr/sbin/postqueue -p>;
for (@data) {
if (/^(\w+)\*?\s/) {
$queue_id = $1;
}
if($queue_id) {
if (/$REGEXP/i) {
$Q{$queue_id} = 1;
$queue_id = "";
}
}
}
#open(POSTSUPER,"|cat") || die "couldn't open postsuper" ;
open(POSTSUPER,"|postsuper -d -") || die "couldn't open postsuper" ;
foreach (keys %Q) {
print POSTSUPER "$_\n";
};
close(POSTSUPER);
--- snip ---
And then use:
% delete-from-mailq "^test"
Tips
[Wayback] How do I check the postfix queue size? – Server Fault
Lots of great answers and pointers to useful guides/software there.
qstat
[Wayback] Postfix Bottleneck Analysis points to [Wayback] Postfix manual – qshape(1): qshape - Print Postfix queue domain and age distribution, then explains about different scenarion and queues:
- [Wayback] Introducing the qshape tool
- [Wayback] Trouble shooting with qshape
- [Wayback] Example 1: Healthy queue
- [Wayback] Example 2: Deferred queue full of dictionary attack bounces
- [Wayback] Example 3: Congestion in the active queue
- [Wayback] Example 4: High volume destination backlog
- [Wayback] Postfix queue directories
postqueue
postqueue -p | tail -n 1Last line in the
postqueue -pshows how many requests and size:
-- 317788 Kbytes in 11860 Requests.
View queues size
I tried finding the original posting of the below script, but could not. If you find it, please let me know.
#!/usr/bin/env perl # postfix queue/s size # author: # source: http://tech.groups.yahoo.com/group/postfix-users/message/255133 use strict; use warnings; use Symbol; sub count { my ($dir) = @_; my $dh = gensym(); my $c = 0; opendir($dh, $dir) or die "$0: opendir: $dir: $!\n"; while (my $f = readdir($dh)) { if ($f =~ m{^[A-F0-9]{5,}$}) { ++$c; } elsif ($f =~ m{^[A-F0-9]$}) { $c += count("$dir/$f"); } } closedir($dh) or die "closedir: $dir: $!\n"; return $c; } my $qdir = `postconf -h queue_directory`; chomp($qdir); chdir($qdir) or die "$0: chdir: $qdir: $!\n"; printf "Incoming: %d\n", count("incoming"); printf "Active: %d\n", count("active"); printf "Deferred: %d\n", count("deferred"); printf "Bounced: %d\n", count("bounce"); printf "Hold: %d\n", count("hold"); printf "Corrupt: %d\n", count("corrupt");
Various commands
[Wayback] Inspecting Postfix’s email queue – Tech-G explaining about:
mailqpostqueue -ppostcat -vq XXXXXXXXXX(whereXXXXXXXXXXis the message ID)postqueue -f/postfix flushpostsuper -dto delete messages
More of these in [Wayback] Postfix Mail Queue Management – Linux Hint and [Wayback] Postfix Bottleneck Analysis: queues.
Makefile
Based on [Wayback] Using “make” for Postfix file maintenance
MAPS = relays.db aliases.db transport.db relocated.db \
virtual.db sender_checks.db rejected_recips.db \
helo_access.db
all : $(MAPS)
aliases.db : aliases
newaliases
%.db : %
postmap $*
This is my Makefile that runs fine on Tumbleweed (note: all 8-space indents are TAB characters):
MAPS = /etc/aliases.db \ transport.db \ virtual.db \ helo_access.db \ canonical.db \ sasl_passwd.db \ relocated.db \ relay.db \ access.db \ relay_ccerts.db \ sender_canonical.db all : $(MAPS) aliases.db : aliases @echo "Rebuilding $@." newaliases %.db : % @echo "Rebuilding $@." postmap $*
In the future, I might try [Wayback] Makefile.postfix · GitHub, though I think it is convoluted:
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| ## Postfix: Makefile to update *.db files | |
| POSTCONF= /usr/sbin/postconf | |
| POSTMAP= /usr/sbin/postmap | |
| default: postmap | |
| postmap: Makefile.postmap | |
| @echo 'Updating database files …' | |
| $(MAKE) -f Makefile.postmap | |
| Makefile.postmap: main.cf | |
| @echo 'Updating $@ …' | |
| @set -e; \ | |
| rm -f $@.$$$$.tmp; \ | |
| echo 'POSTMAP=$(POSTMAP)' >>$@.$$$$.tmp; \ | |
| echo 'postmap::' >>$@.$$$$.tmp; \ | |
| config_directory="$(PWD)"; \ | |
| { $(POSTCONF) -c $(PWD) || kill $$$$; } \ | |
| |tr ' ' '\n' \ | |
| |sed -n \ | |
| -e 's/,$$//' \ | |
| -e 's#^hash:\$$config_directory/##p' \ | |
| -e 's#^hash:'"$$config_directory/##p" \ | |
| |sort -u \ | |
| |while read mapfile; do \ | |
| echo "postmap:: $$mapfile.db" >>$@.$$$$.tmp; \ | |
| echo "$$mapfile.db: $$mapfile" >>$@.$$$$.tmp; \ | |
| echo " \$$(POSTMAP) $$<" >>$@.$$$$.tmp; \ | |
| done; \ | |
| mv $@.$$$$.tmp $@ |
[Wayback] Ralf Hildebrandt
Ralf Hildebrandt is an active and well-known figure in the Postfix community. He’s a systems engineer for T-NetPro, a German telecommunications company and has spoken about Postfix at industry conferences and contributes regularly to a number of open source mailing lists.
Co-author of this book: [Wayback: Book of Postfix State-of-the-Art Message Transport ISBN 9781593270018] (which used to have its own site: [Wayback: The Book of Postfix]
Book of Postfix
State-of-the-Art Message Transport
Publisher: No Starch PressRelease Date: March 2005Pages: 496 Best practices for Postfix–the popular alternative to Sendmail. Developed with security and speed in mind, Postfix has become a popular alternative to Sendmail and comes preinstalled in many Linux distributions as the default mailer. The Book of Postfix is a complete guide to Postfix whether used at home, as a mailrelay or virus-scanning gateway, or as a company mailserver. Practical examples show how to deal with daily challenges like protecting mail users from spam and viruses, managing multiple domains, and offering roaming access.
This is a great review of the book: [Wayback] The Book of Postfix (Ralf Hildebrandt, Patrick Koetter)
Related
For my postfix studies… « The Wiert Corner – irregular stream of stuff
–jeroen
The Wiert Corner - irregular stream of stuff 
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