if (/From:/) {
  m/^\w+:(\S+)$/ && push my @addr, Mail::Address->parse($1);
  $address = $addr[0]->address;
  $debug_text .= "Found $address at line $.\n";
}

##</code><code>##

       s/PATTERN/REPLACEMENT/egimosx
                   s   Treat string as single line.
                   g   Replace globally, i.e., all occurrences.

##</code><code>##

if (/^From:(\S+)$/) {
  push my @addr, Mail::Address->parse($1);
  $address = $addr[0]->address;
  $debug_text .= "Found $address at line $.\n";
} else { next }