From address does not default to contact's email (Improvement Request)
When "Allow Mail to be sent from logged in contact's email address" (Administer | System Settings | Outbound mail) is Yes (and an new email is opened to be sent to a contact, the default From address is the user's primary email address, as expected.
When this flag is No, however, the default is the first email address in the From Senders, even if the user has a primary address which is in the From Senders list.
Same issue with CiviMail, although in that case the default From address is always the first address in the From Senders, even when the above flag is Yes.
8/9/19: Edit: Change "unchecked" to "Yes" and "checked" to "No".