Even though I'm not in the publication business, I still have the same dilemma sometimes as you. And the way, I look at this situation is this- I normally don't send my portfolio of architectural plans/drawings I have created/completed for either scholastic or work roles. The reason is because I in my well-written cover letter I will say: "Please feel free to contact me for additional materials that may assist your decision making for the ____ position." Basically, I want to know they are interested by contacting me for either an interview over the phone or in-person, and/or for mat'ls like references/portfolio samples, or an updated resume. Because if they are truly interested in giving you a position based on your qualifications, they will contact you and your portfolio should be used to reaffirm your talents and experiences you have.
Hope you and others find this helpful.
T. M.