Is this your entire script? No use strict; or use warnings; Did you read the module documentation? Did you try the example that comes with the distribution (demos/pop3)? Why are you declaring $pop twice, once after the other, the difference being that the second declaration includes the Timeout option in the constructor? This looks like a copy and paste from the documentation, rather than reading the documentation and understanding what it is telling you. On this note, since you are having problems you could enable debugging:

my $pop = Net::POP3->new('pop3host', Timeout => 60, Debug => 1);

Are you sure the server in question supports pinging? Have you checked via the capabilities() method mentioned in the documentation?

Perhaps taking a step back and rereading the documentation, and reading some of the basic tutorials here will help you.

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Martin