Blog Comment Problems

Hello everybody... I have received several emails this month saying that some of you tried to post a comment and could not post one for some reason or another. If you are someone who has been able to post and are familiar with problems of this sort.. could you leave a comment below on what might be the problem and how I go about fixing it? I have tried different things and still can not figure out why some people can post and some people can not. Anyway, any suggestions are greatly appreciated! Thanks. Also, feel free to email me if you want at sarahchristoph81@gmail.com Thanks!