Intimation under section 143(1)

dear sir/mam,
i get intimation under section 143(1) via email on 26.05.2017 of A.Y. 2015-16  file before 31/March/2017 but i found all columns with values are same.in column As Provided by Taxpayer in Return of Income -> total income tax liablity is zero and in column As Computed Under Section 143(1) -> total tax liability is also zero.i do not understand where is mimatch and what the department has asked me or just it is an acknowledgement.

thanks