 Mimecast Limited MIME, a leading email and data security company, is set to join the broad-market Russell 3000 Index at the conclusion of the 2020 Russell indexes annual reconstitution, effective after the U.S. market opens on June 29, 2020 according to a preliminary list of additions posted June 5, 2020. Annual Russell indexes reconstitution captures the 4,000 largest US stocks as of May 8, 2020 ranking them by total market capitalization. Membership in the U.S. all-cap Russell 3000 Index, which remains in place for one year, means automatic inclusion in the large-cap Russell 1000 Index or small-cap Russell 2000 Index as well as the appropriate growth and value style indexes. 