Which protocol specifically allows access to emails stored on a mail server?

IMAP, or Internet Message Access Protocol, is specifically designed for accessing emails stored on a mail server. Unlike other protocols, IMAP allows users to not only retrieve emails but also manage them directly on the server. This means that actions like organizing emails into folders, marking them as read or unread, and deleting them can all be performed without downloading the emails to the local device. This is particularly beneficial for users who need to access their emails from multiple devices, as any changes made on one device are reflected across all devices.

In contrast, SMTP (Simple Mail Transfer Protocol) is primarily used for sending emails, not for accessing or retrieving them. POP (Post Office Protocol), while it does allow access to emails as well, downloads them to the local machine and typically deletes them from the server, which can be less efficient for users who want to keep their emails synchronized across different devices. HTTP (Hypertext Transfer Protocol) is used for web traffic and is not designed for email access at all. Thus, IMAP is the most suitable protocol for accessing and managing emails directly on a mail server.