$/ = "From mailsnarf\n";
while(defined(my $para = <$infile>)) {
  # ...
}
[download]

Update: Or, if it won't always be 'mailsnarf'... (Note: Untested)

while(defined(my $line = <$infile>)) {
  next if($line =~ /^From (\w+)$/ ... $line =~ /^From (\w+)$/);
  # ...
}
[download]

bbfu
Seasons don't fear The Reaper.
Nor do the wind, the sun, and the rain.
We can be like they are.