By e-mail or post?
Most publications accept work by e-mail but some still prefer postal submissions, especially from someone writing for them for the first time. Even if you have had a few pieces published by a magazine, if they ask for submissions to be sent by post, send your work by post. You could always send a query e-mail asking if they’d be prepared to accept future work by e-mail. If you just go ahead and send your full piece by e-mail, the editor may have a policy where any submission sent this way is automatically deleted so you could find your work isn’t even looked at.