Very few of such sites (Online sites for watching anime/reading manga) are legal. There's a giant legal blur over these sites because the law changes from country to country and from site to site based on usage.
For that reason we decided to avoid the trap hole and disallow these questions completely.
Unless the site in question is official, and the question is constructive (i.e.not "Should I use this site?"), it's probably not welcome here. If your question answers the above criteria, go ahead and ask it! We'll be happy to answer it.
As for My Anime List specifically, it's very likely that any question you may ask here is either off-topic (as it should be directed to their support), or not constructive (as it would be a recommendation question).
So here's what you do, ask it anyway. At the worst case, it would be closed.