MIME::Lite is not core Perl

Mail::Sendmail isn't core perl either, but it is pure Perl, so installing it is simply a matter of putting the .pm file where Perl can find it, or failing that putting it in the same directory as your script and prepending a use lib statement. I don't know whether the same is also true of MIME::Lite, but Mail::Sendmail is quite simple to use in any case, when all you need to do is fire off an email message.