This might be in a state of flux. I am getting a 404 error trying to load the example docs I had from before. As I mentioned, I have an open ticket on this issue, as my opinion is that if they offer 'tests' then their tests should perform exactly like the languages they are testing.

The code I wrote was such:

#!/usr/bin/perl

use strict;
use warnings;

my (@res);
while(<>){
    my @add = $_ =~ /([\w\.]+\@[\w]+\.[\w]+.*?)[^\w\.]/g;    
    $_ =~ s/\.$// for @add;
    push @res, @add;
}
my %uniq;
$uniq{$_}++ for @res;
@res = sort  keys %uniq;

print join ";", @res;
[download]

The input data was this:

51
E-MAIL ADDRESSES OF GMs AND DRMs ON IR
RLY    GM E-Mail    Division    DRM E-Mail
CR    gm@cr.railnet.gov.in    Mumbai    drm@bb.railnet.gov.in
Bhusawal    drm@bsl.railnet.gov.in
Pune    drm@pa.railnet.gov.in
Nagpur    drm@ngp.railnet.gov.in
Solapur    drm@sur.railnet.gov.in
ER     gm@er.railnet.gov.in    Howrah    drmhwh@er.railnet.gov.in
Sealdah    drmsdah@er.railnet.gov.in
Asansol    drmasn@er.railnet.gov.in
Malda    drmmldt@er.railnet.gov.in
ECR     gm@ecr.railnet.gov.in    Danapur    drmdnr@ecr.railnet.gov.in
Dhanbad    drmdhn@ecr.railnet.gov.in
Mughalsarai    drmmgs@ecr.railnet.gov.in
Samastipur    drmspj@ecr.railnet.gov.in
Sonpur    drmsee@ecr.railnet.gov.in
ECoR        gm@eastcoastrailway.gov.in      Khurda Road    drmkur@east
+coastrailway.gov.in
Sambalpur    drmsbp@eastcoastrailway.gov.in
Waltair    drmwat@eastcoastrailway.gov.in
NR     gm@nr.railnet.gov.in    Delhi    drm@dli.railnet.gov.in
Ambala    drm@umb.railnet.gov.in
Moradabad    drm@mb.railnet.gov.in
Lucknow    drm@lko.railnet.gov.in
Ferozepur    drm@fzr.railnet.gov.in
NCR        gm@ncr.railnet.gov.in      Allahabad    drm@ald.railnet.gov
+.in
Jhansi    drm@jhs.railnet.gov.in
Agra    drm@agc.railnet.gov.in
NER    gm@ner.railnet.gov.in    Izzatnagar    drmizn@ner.railnet.gov.i
+n
Lucknow    drmljn@ner.railnet.gov.in
Varanasi    drmbsb@ner.railnet.gov.in
NFR    gm@nfr.railnet.gov.in    Katihar    drmkir@nfr.railnet.gov.in
Alipurduar    drmapdj@nfr.railnet.gov.in
Tinsukhia    drmtsk@nfr.railnet.gov.in
Lumding    drmlmg@nfr.railnet.gov.in
Rangia    drmrny@nfr.railnet.gov.in
NWR    gm@nwr.railnet.gov.in    Jaipur    drmjp@nwr.railnet.gov.in
Ajmer    drmaii@nwr.railnet.gov.in
Bikaner    drmbkn@nwr.railnet.gov.in
Jodhpur    drmju@nwr.railnet.gov.in
SR    gm@sr.railnet.gov.in    Chennai    drmmas@sr.railnet.gov.in
Madurai    drmmdu@sr.railnet.gov.in
Salem    drmsa@sr.railnet.gov.in
Palghat    drmpgt@sr.railnet.gov.in
Tiruchirapalli    drmtpj@sr.railnet.gov.in
Trivandrum    drmtvc@sr.railnet.gov.in
SCR    gm@scr.railnet.gov.in    Secundrabad    drmsc@scr.railnet.gov.i
+n
Hyderabad    drmshyb@scr.railnet.gov.in
Guntkal    drmgtl@scr.railnet.gov.in
Guntur    drmgnt@scr.railnet.gov.in
Nanded    drmned@scr.railnet.gov.in
Vijayawada    drmbza@scr.railnet.gov.in
[download]

The expected results were:

drm@agc.railnet.gov.in;drm@ald.railnet.gov.in;drm@bb.railnet.gov.in;dr
+m@bsl.railnet.gov.in;drm@dli.railnet.gov.in;drm@fzr.railnet.gov.in;dr
+m@jhs.railnet.gov.in;drm@lko.railnet.gov.in;drm@mb.railnet.gov.in;drm
+@ngp.railnet.gov.in;drm@pa.railnet.gov.in;drm@sur.railnet.gov.in;drm@
+umb.railnet.gov.in;drmaii@nwr.railnet.gov.in;drmapdj@nfr.railnet.gov.
+in;drmasn@er.railnet.gov.in;drmbkn@nwr.railnet.gov.in;drmbsb@ner.rail
+net.gov.in;drmbza@scr.railnet.gov.in;drmdhn@ecr.railnet.gov.in;drmdnr
+@ecr.railnet.gov.in;drmgnt@scr.railnet.gov.in;drmgtl@scr.railnet.gov.
+in;drmhwh@er.railnet.gov.in;drmizn@ner.railnet.gov.in;drmjp@nwr.railn
+et.gov.in;drmju@nwr.railnet.gov.in;drmkir@nfr.railnet.gov.in;drmkur@e
+astcoastrailway.gov.in;drmljn@ner.railnet.gov.in;drmlmg@nfr.railnet.g
+ov.in;drmmas@sr.railnet.gov.in;drmmdu@sr.railnet.gov.in;drmmgs@ecr.ra
+ilnet.gov.in;drmmldt@er.railnet.gov.in;drmned@scr.railnet.gov.in;drmp
+gt@sr.railnet.gov.in;drmrny@nfr.railnet.gov.in;drmsa@sr.railnet.gov.i
+n;drmsbp@eastcoastrailway.gov.in;drmsc@scr.railnet.gov.in;drmsdah@er.
+railnet.gov.in;drmsee@ecr.railnet.gov.in;drmshyb@scr.railnet.gov.in;d
+rmspj@ecr.railnet.gov.in;drmtpj@sr.railnet.gov.in;drmtsk@nfr.railnet.
+gov.in;drmtvc@sr.railnet.gov.in;drmwat@eastcoastrailway.gov.in;gm@cr.
+railnet.gov.in;gm@eastcoastrailway.gov.in;gm@ecr.railnet.gov.in;gm@er
+.railnet.gov.in;gm@ncr.railnet.gov.in;gm@ner.railnet.gov.in;gm@nfr.ra
+ilnet.gov.in;gm@nr.railnet.gov.in;gm@nwr.railnet.gov.in;gm@scr.railne
+t.gov.in;gm@sr.railnet.gov.in
[download]

My results in a shell are identical to those results. The missing address is the 'drmbza@scr.railnet.gov.in' in their minds.

It seems the behaviour depends on whether the file ends in a newline or not, not on the Perl version. That's because the final [^\w\.] has nothing to match if there's no newline.

If you are curious, here's my solution from three years ago:

<Reveal this spoiler or all in this thread>

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
[download]

But that code actually works. It returns the expected results, including the terminal email address. It just doesn't on hackerrank.com. It did when I changed [^\w\.] to (?:$|[^\w\.]), which is what the regex site needed.

If it's not a Perl version thing, then it's likely some kind of emulator issue on their part, or perhaps the regex web site is wrong in not matching it. It seems to me that EOD is not a word, personally.