Just to expand on dragonchild's comment, I'd be inclined to create a package for each kind of account, with a "new" method to create a blessed object from the data in the original text file. Each $accounts{ssn} would contain an anonymous array of these objects. Creating %accounts might be done as follows:

while (<>) {
    my($ssn, $obj) = parse_account($_);
    push @{$accounts{$ssn}}, $obj;
}
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parse_account() of course would have to be able to determine the account type that the string defines, then call the appropriate account-object constructor. Each individual account-type package would provide a standard set of methods to access account information. E.g. to print out all the email addresses you'd implement a method called "email" within each package; it could be called like this:

while (my($ssn, $acctlist) = each %accounts) {
    foreach my $acct (@$acctlist) {
        print $ssn, $acct->email, "\n";
    }
}
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A simple, individual "email" method would just look like:

sub email {
    my $self = shift;
    return $self->{'email'};
}
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If you wanted to get fancy, all of the individual account-type packages could inherit from a more generic package; this would let you avoid having to create all these duplicate trivial methods.