The document summarizes key developments in email clients and the email industry in 2018. Some of the key points include:
1. Apple's iOS Mail and Gmail continued to dominate email client market share in 2018, capturing 29% and 27% of opens respectively. Outlook saw steady growth, increasing its share to 8%.
2. Mobile remained the most popular way to read email, accounting for 43% of opens, though its share declined slightly over the year.
3. Changes to Yahoo Mail's infrastructure, which began merging with AOL, led to a significant increase in opens through Yahoo Mail, accounting for its rising share.