co.jp vs ImprovMX

ImprovMX is used by more websites in our catalog: 205 use co.jp and 867 use ImprovMX.

co.jp sites have the higher median Ahrefs Domain Rating (co.jp: 60, ImprovMX: 23).

Between 2026-06 and 2026-07, co.jp went from 0.03% to 0.02% of all tracked sites, while ImprovMX went from 0.12% to 0.10%. co.jp is gaining ground faster in our index.

No. A site runs a single email host, so co.jp and ImprovMX are mutually exclusive.

Adoption is counted from Site Stats Database's own crawl; Domain Rating comes from Ahrefs and traffic from DataForSEO. Figures reflect the sites we track and refresh at least monthly.