ImHO, it's not a very beautiful way for your files to communicate via global variables, especially if they are set by the main script in the main namespace. And the double-colon form is quite error-prone, which is demonstrated by your problem.

I don't know what exactly you are designing, but maybe the best approach would be an OO constructor, like this:

# Pit.pm
package Pit;
use strict;

sub new {
    my ($class, $email) = @_;
    return bless {
        email => $email,
    };
}

sub printIT {
    my $this = shift;
    print '2) ', $this->{email}, "\n";
}

# main script:
use strict;
use Pit;

my $pit = Pit->new('me@example.com');
$pit->printIT;
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By the way, note the capital "P" in the package name, which is the most common and recommended form to write a package name. And note that the package file needs it's own "use strict" because the line from the main script is not effective there. (Same thing with warnings.)