Just one quick thought: 
$data =~ s/\s+/ /g;
$data =~ s/  +//g;
# remove leading and trailing blanks
$data =~ s/^\s+//;
$data =~ s/\s+$//;

[download]
What you do here is first to substitute any whitespace characters by blanks, then all blanks by nothing and then you look for blank at the beginning and the end of your data. As your RegEx to validate input is $data =~ /^([-\@\w. ]+)$/, I would guess that you might have wanted to leave the second RegEx out. If not so, you could just substitute all four of them by $data =~ s/\s+//g;.
Also, your RegEx for validation could be rewritten using negated charachter classes, for example if ($data !~ /[^-\@\w. ]/) { ..., but that's just a question of personal preference.
You code looks fine to me, but always keep in mind that untainting data depends on what you do with it afterwards.
Cheers,
CombatSquirrel.
Entropy is the tendency of everything going to hell.

In reply to Re: Check input sub - comments please... by CombatSquirrel
in thread Check input sub - comments please... by kiat

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