I use Mail::Address from MailTools for this.

use Mail::Address;
my $string = 'To: someone <someemail@somedomain.tld>, "someone else" <
+someoneelse@some.other.domain>, info@somewhere.com (info address)';
my @address = map $_->address, Mail::Address->parse($string);
{
    local $\ = "\n";
    print for @address;
}
[download]

Result:

someemail@somedomain.tld
someoneelse@some.other.domain
info@somewhere.com