iCloud Mail

Apple Mail (officially known as Mail) is an email client included by Apple Inc. with its operating systems macOS, iOS, iPadOS and watchOS. Apple Mail grew out of NeXTMail, which was originally developed by NeXT as part of its NeXTSTEP operating system, after Apple’s acquisition of NeXT in 1997.
The current version of Apple Mail utilizes SMTP for message sending, POP3, Exchange and IMAP for message retrieval and S/MIME for end-to-end message encryption. It is also preconfigured to work with popular email providers, such as Yahoo! Mail, AOL Mail, Gmail, Outlook and iCloud (formerly MobileMe) and it supports Exchange. iOS features a mobile version of Apple Mail with added Exchange ActiveSync (EAS) support, though it notoriously missed the functionality of attaching files to reply emails until the release of iOS 9. EAS is not supported in the macOS version of Apple’s Mail app, the main issue being that sent messages will incorrectly be duplicated in the sent messages folder, which then propagates via sync to all other devices including iOS.
Features of Apple Mail include the ability to configure the software to receive all of a user’s email accounts in the one list, ability to file emails into folders, ability to search for emails, and ability to automatically append signatures to outgoing emails. It also integrates with the Contacts list, Calendar, Maps and other apps.