First, learn to use the formatting tools available. In particular, you should have noticed when you hit 'preview' that your text had run together. You probably wanted that in code tags.

Second:

#!/usr/bin/perl
use strict;
use warnings;
while (<>) {
    print "found '$1'\n" if /:([^;]+)/;
}
__END__
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which when given the input file you describe via a call like

./foo.pl input_file
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will print

found ' karemaips01'
found ' karemadom02'
found ' karemadbo01'
found ' karemadom01.emea.pfizer.com'
found ' karemasss05'
found ' ka-lvsapp'
found ' emakars001.pfizer.com'
found ' ka-lvsn1'
found ' ka-efss'
found ' ka-lvsn2'
found ' karemafil-c'
found ' ka-lvscluco'
found ' ka-lvsdb'
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