Please see if the articles were not less than three hundred words, not copied form other sites/ books and not offensive to any one or not vulgar. 

You can also mail boddunan support to get down to know the real reason. At times if the naming of the article is not done appropriately or the category is not suitable the article gets rejected.

Hi Piush- Please let me know if you're missing something in particular. I know you write very well on sites you mentioned plus some other sites you did not mention.

I can not see links of your rejected articles hence cannot offer any comment on why they were rejected but the reasons could be anywhere from too many grammar or spelling errors or length of articles not meeting expectations etc. There is usually a reason provided which you can when you hover the cursor over Rejected status.

The reasons will be mentioned on the article itself. If your article did not have grammar mistakes and if you put any images without mentioning the source of the link the article will likely to be rejected. If you did not mention the image source at the end of the article please mention it.

@Peeush I saw your first article today, sorry but it does not qualify as an article being too short and almost bookish. Better go through few of the published articles before submitting your next.