In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. Today, POP version 3 (POP3) is the most commonly used version. Together with IMAP, it is one of the most common protocols for email retrieval.
An email client, email reader or, more formally, message user agent (MUA) or mail user agent is a computer program used to access and manage a user's email.
GNOME Evolution is the official personal information manager for GNOME. It has been an official part of GNOME since Evolution 2.0 was included with the GNOME 2.8 release in September 2004. It combines e-mail, address book, calendar, task list and note-taking features. Its user interface and functionality is similar to Microsoft Outlook. Evolution is free software licensed under the terms of the GNU Lesser General Public License (LGPL).
Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft 365 software suites. Though primarily being popular as an email client for businesses, Outlook also includes functions such as calendaring, task managing, contact managing, note-taking, journal logging, web browsing, and RSS news aggregation.
Outlook Express, formerly known as Microsoft Internet Mail and News, is a discontinued email and news client included with Internet Explorer versions 3.0 through 6.0. As such, it was bundled with several versions of Microsoft Windows, from Windows 98 to Windows Server 2003, and was available for Windows 3.x, Windows NT 3.51, Windows 95, Mac System 7, Mac OS 8, and Mac OS 9. In Windows Vista, Outlook Express was superseded by Windows Mail.
Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems.
Microsoft Entourage is a discontinued e-mail client and personal information manager that was developed by Microsoft for Mac OS 8.5 and later. Microsoft first released Entourage in October 2000 as part of the Microsoft Office 2001 office suite; Office 98, the previous version of Microsoft Office for the classic Mac OS included Outlook Express 5. The last version was Entourage: Mac 2008, part of Microsoft Office 2008 for Mac, released on January 15, 2008. Entourage was replaced by Outlook for Macintosh in Microsoft Office for Mac 2011, released on October 26, 2010.
Transport Neutral Encapsulation Format or TNEF is a proprietary email attachment format used by Microsoft Outlook and Microsoft Exchange Server. An attached file with TNEF encoding is most often named winmail.dat or win.dat, and has a MIME type of Application/MS-TNEF. The official (IANA) media type, however, is application/vnd.ms-tnef.
Push email is an email system that provides an always-on capability, in which when new email arrives at the mail delivery agent (MDA), it is immediately, actively transferred (pushed) by the MDA to the mail user agent (MUA), also called the email client, so that the end-user can see incoming email immediately. This is in contrast with systems that check for new incoming mail every so often, on a schedule. Email clients include smartphones and, less strictly, IMAP personal computer mail applications.
The following tables compare general and technical information for a number of notable webmail providers who offer a web interface in English.
Windows Live Mail is a discontinued freeware email client from Microsoft. It was the successor to Windows Mail in Windows Vista, which was the successor to Outlook Express in Windows XP and Windows 98. Windows Live Mail is designed to run on Windows 7 and Windows Server 2008 R2, but is also compatible with Windows 8 and Windows 10, even though Microsoft bundles a new email client, named Windows Mail, with the latter. In addition to email, Windows Live Mail also features a calendar, an RSS feed reader, and a Usenet newsreader.
MobileMe is a discontinued subscription-based collection of online services and software offered by Apple Inc. All services were gradually transitioned to and eventually replaced by the free iCloud, and MobileMe ceased on June 30, 2012, with transfers to iCloud being available until July 31, 2012, or data being available for download until that date, when the site finally closed completely. On that date all data was deleted, and email addresses of accounts not transferred to iCloud were marked as unused.
Exchange ActiveSync is a proprietary protocol designed for the synchronization of email, contacts, calendar, tasks, and notes from a messaging server to a smartphone or other mobile devices. The protocol also provides mobile device management and policy controls. The protocol is based on XML. The mobile device communicates over HTTP or HTTPS.
iCloud is a cloud service developed by Apple Inc. Launched on October 12, 2011, iCloud enables users to store and sync data across devices, including Apple Mail, Apple Calendar, Apple Photos, Apple Notes, contacts, settings, backups, and files, to collaborate with other users, and track assets through Find My. It is built into iOS, iPadOS, watchOS, tvOS, macOS, and visionOS. iCloud may additionally be accessed through a limited web interface and Windows application.
iMessage is an instant messaging service developed by Apple Inc. and launched in 2011. iMessage functions exclusively on Apple platforms – including macOS, iOS, iPadOS, and watchOS – as part of Apple's broader strategic approach to inter device integration, sometimes referred to as the Apple Eco-System.
Messages is a text messaging software application developed by Apple Inc. for its macOS, iOS, iPadOS, watchOS, and visionOS operating systems.
Notes is a notetaking app developed by Apple Inc. It is provided on the company's iOS, iPadOS, visionOS, and macOS operating systems, the latter starting with OS X Mountain Lion. It functions as a service for making short text notes, which can be synchronized between devices using Apple's iCloud service. The application uses a similar interface on iOS and macOS, with a non-textured paper background for notes and light yellow icons, suggesting pencil or crayon. Until 2013, both applications used a strongly skeuomorphic interface, with a lined, textured paper design; the Mountain Lion version placed this inside a leather folder. This design was replaced in OS X Mavericks and iOS 7.
Kopano is an open-source groupware application suite originally based on Zarafa. The initial version of Kopano Core (KC) was forked from the then-current release of Zarafa Collaboration Platform, and superseded ZCP in terms of lineage as ZCP switched to maintenance mode with patches flowing from KC. Kopano WebApp similarly descended from Zarafa WebApp. Since October 2017, Kopano Core is also known more specifically as Kopano Groupware Core, since Kopano B.V. developed more products that were not directly requiring groupware components.
