In a previous blog post, we discussed how email threads are typically managed on the client side, as virtual entities. Previous attempts to define server-side threading, such as the RFC5256 standard, were mainly useful for mailing-list type threads, assuming that all related emails were located in the same folder. This
All larger email providers are slowly but steadily moving away from regular password-based authentication for email protocols like IMAP and SMTP. There are multiple options to do so. For example, iCloud requires you to generate application passwords for IMAP. Gmail is pushing OAuth2, even though it also allows application passwords.