For the new Yahoo Mail (June 2017 version), I cannot figure out a way to copy and paste multiple email addresses when composing a new email. I tried delimiting with semicolons, commas, and spaces, but it only retains the first and last email in the "To" field. For example:
user1@yahoo.com; user2@yahoo.com; user3@yahoo.com
user1@yahoo.com, user2@yahoo.com, user3@yahoo.com
user1@yahoo.com user2@yahoo.com user3@yahoo.com
Will result in this (only the first and last emails are retained):
This used to work with the previous "Classic Yahoo Mail" (prior to June 2017 version).