Wow that is quite long. One comment: In stead of this:

my @sLart;              #Assembly for the elements of the email
my @aoaCheck;           #Array of checkbox data
                        #[][0] is the checkbox itself
                        #[][1] is the 'ticked' variable
                        #[][2] is the text
my $nLandings = 0;      #Number of landing points analysed
my $sServer;            #Whois server
my %hoaBank;            #Hash of Arrays of banks
my $sBank;              #Selected bank from combobox
my $sTo;                #Email address of $sBank
my $sFrom;              #Spamgourmet prefix for $sBank
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it is usually better to declare your variables where you use them first (that way, and with strict, you get a nice warning when you double-use a variable name).