I work for an ISP with our own propriatary SMTP Daemon, one night our Daemon crashed and stayed down for 2 hours, in the mean time sendmail came up, started processing all the messages and (not being able to send them) dumped them all to a dead.letter file (150 Mb).

Using the following script (wrote it in 10 mins Whoohoo!) we were able to extract all the messages, including bodyparts, and send them to our customers:

#!/usr/local/bin/perl -w

use strict;

$| = 1;
my @Message;
my $MsgId;
my $Found;
my $Number=0;

while(<>)
{
 if (/^Return-Path:/)
 {
  $Found=0;
  push @Message, $_;
  while(<>)
  {
   push @Message,$_;

   last if (($Found==1)&&(/^--$MsgId\S*--/));

   if ((/internal id (\S+);/)&&($Found==0))
   {

    $MsgId=$1;
    $Found=1;
   };
  };

  open FILE,">good/$MsgId.$Number.msg" or die "Error writing to $MsgId
+.msg\n";
  print FILE @Message;
  close FILE;

  @Message="";
  $Number++;
 };

};
[download]

Edited by dws to add <code> tags