Poprelay is a service that allows your Dovecot pop users to also send e-mails through your sendmail SMTP server on the same machine. When they check their e-mails, their IP address is logged in a database. Once the same user wants to send an e-mail using your SMTP port, then sendmail checks this database and if the IP is present, then the relay is allowed. This makes it completely transparent to the user and the server will still be very secure and blocking all other IP addresses for relaying. The IP address is kept in the database for about 15 minutes only, so there is no chance for anyone else to use the same IP address and server. 
Dated 2005-08-19 you can now use this poprelay service with Dovecot. 
The main page of poprelayd is the following: http://sourceforge.net/projects/poprelay 
Download the latest source there. You have an install script that does almost everything for you. You still need some manual intervention to add some required lines in your sendmail.mc file. This is described in the install documentation. Once this is done, you will have to replace your /etc/mail/poprelay.conf file by the lines below. Once this is done restart the poprelay service and it should be working. 
Please report any problem on the poprelay forum. You will need to leave the v6-mapped ip4 address in the /etc/mail/maillog for the moment (e.g. you should see '[::ffff:IP_ADDRESS]' in the pop user's login logs). 
You might have to adapt the first configuration lines if you are using something else than CentOS 4. 

---%<-------------------------------------------------------------------------
 
#This file is interpreted by perl 
#you can do a quick syntax check by doing "perl poprelay.conf" 
 
#=======================Standard configuration options===================== 
 
# where POP3/IMAP daemon connections get logged 
$logfile = "/var/log/maillog"; 
 
 
# Where we put our PID. (dieing output 
# will be dumped here too) 
$pidfile = "/var/run/poprelayd.pid"; 
 
 
# Sendmail map to update. 
$dbfile = "/etc/mail/popip.db"; 
 
 
#Change this to match the type of db file sendmail needs 
#Your perl must support that type of file as well 
$dbtype = "DB_HASH"; 
 
# Minutes an entry lasts. (3000 = ~ 2 days) 
# IMAP connections can last a very long time so I like to keep this long. 
# The odds that someone will hop onto one of your valid user's old IP's and 
# spam from it are so small I wouldn't worry about it. I recommend making 
# this long to avoid complications. 
$timeout_minutes = 15; 
 
 
# Number of seconds to sleep between checks 
$log_wait_interval = 5; 
 
 
#=======================Advanced configuration options===================== 
 
#Alternate log line parsers: 
 
#There can be only one log parser. 
#the standard one should work for most systems. The other 
#ones may be slightly out of date. I don't have any systems 
#that run these servers so I can't update or test the routines. 
#If you fix anything with them please let me know and I will 
#roll the changes into the main version. 
# 
#$log_parser = \&log_parse_standard; 
#$log_parser = \&log_parse_berkeley; 
#$log_parser = \&log_parse_qpopper; 
#$log_parser = \&log_parse_qpopper_old; 
#$log_parser = \&log_parse_cucipop; 
$log_parser = \&log_parse_custom; 
 
#Custom log line parsing scripts: 
 
#If you want to create your own log parsing routine, do it here in 
#the config file so you can update the poprelayd without losing your 
#custom parsing routine. The routine below does the same thing as 
#log_parse_standard. It should be a good starting point for any 
#customization. It parses lines in many stages so it can be easily 
#customized. It will even do dns lookups of hostnames using 
#gethostbyname if the program logs the hostname instead of the ip. 
# 
#If you get something working post it to the forums at 
#http://sourceforge.net/projects/poprelay so the next guy doesn't have 
#to go through the same headache. I'll try and roll new routines into 
#the main program so that poprelayd can work out of the box for all 
#the log formats. 
 
# Dovecot maillog parser: 
sub log_parse_custom ($) { 
  my $s = $_[0]; 
  my @paddrs; # Packed IP addresses. 
  my @addrs; # ASCII addresses. 
  my ($junk,$info,$string,$service,$ip,$host); 
  ($info, $string)=split(/\: /,$line); 
  ($service) = $info=~/(\S+)$/; 
  $service=~s/\[\d+\]//; 
  return () unless $service=~/^(pop2|pop3|imap)-login$/; 
  return () unless $string=~/^(Login|Authenticated)/; 
  ($ip) = $line=~/.*\:\:ffff\:(\d+\.\d+\.\d+\.\d+)\]/; 
  if ($ip) { 
    print "$service: $ip\n"; 
    return ($ip); 
  } else { 
    ($host) = $string=~/^(\S+)/; 
    print "$service: $host\n"; 
    ($junk, $junk, $junk, $junk, @paddrs) = gethostbyname($host); 
    while (@paddrs) { 
      push(@addrs, join('.', unpack('C4', shift(@paddrs)))); 
    } 
    return (@addrs); 
  } 
} 
 
#leave this alone: 
1; 
---%<-------------------------------------------------------------------------

(This file was created from the wiki on 2007-12-11 04:42)
