Sometimes in your Referring Domains or Backlinks report, you might see that you have a link from a domain with a DR of 0 (or N/A or some small number): 

Does this mean that this site is spammy and you should consider disavowing it? 

The answer is: no. 

Domain Rating shows the strength of a target website’s total backlink profile (in terms of its size and quality). It is not a measure of a website’s quality and legitimacy. 

You cannot rely on this metric alone to determine if a website is spammy or not. 

Plus, new legitimate websites that have yet to build links can also have a very low DR score, and that does not mean that they are spammy websites. 

The best way to check is still to do a manual analysis. You can follow this guide on how to determine if a link is spammy.