In email technology, IDLE is an IMAP feature described in RFC 2177 that allows a client to indicate to the server that it is ready to accept real-time notifications.
The IDLE feature allows IMAP email users to immediately receive any mailbox changes without having to undertake any action such as clicking on a refresh button, or having the email client automatically and repeatedly ask the server for new messages.
IMAP4 servers that support IDLE will include the programming string "IDLE" in the result of their CAPABILITY command. This allows email users to receive near instant notification of a new email.
Client software with support for IMAP IDLE
Airmail for OS X
Apple Mail, IDLE command introduced with version 3.
Becky!, IDLE command introduced with version 2.56 (2010/09/29).
Cone
Courier
eM Client
EmailPush for iPhone
Emansio For Windows Mobile
Evolution (IMAPX introduced as "IMAP+" in version 2.30)
FlexMail For Windows Mobile
ibisMail for iPhone
i.Scribe / InScribe
K-9 Mail for Android
Kaiten Mail for Android
Kmail as with KDE SC 4.7
Mailbird
Mail application on Nokia N9
MetroMail for Windows Phone 8
Microsoft Entourage
Microsoft Outlook
Microsoft Outlook Express
Microsoft Windows Mail
Microsoft Windows Mail App for Windows 8
Mozilla Thunderbird/SeaMonkey
Mutt
Opera Mail
Peek (mobile email device)
ProfiMail For Windows Mobile and Symbian
SchedHandler For Windows Mobile
Sparrow for OS X
Symbian smartphones
Tiverias GPush for iPhone
Treo smartphones
The Bat
Trojitá
webOS smartphones
Zimbra Desktop for Windows, Linux & MAC
Server software with support for IMAP IDLE
acIMAP
Archiveopteryx
CommuniGate Pro
ContactOffice
Courier Mail Server
Cyrus IMAP server
Davmail Gateway
DBMail IMAP and POP3 server
dovecot IMAP server
Eudora Internet Mail Server
hMailServer
IceWarp Mail Server
isode M-Box POP/IMAP Gateway
Kerio Connect (formerly Kerio MailServer
Kolab Groupware Server
LumiSoft Mail Server
MailEnable
MailSite
Mailtraq
MDaemon Mail Server
Mercury 32
Microsoft Exchange Server
Panda IMAP
SmarterMail 8.x
Sun Java System Messaging Server
Synchronica Mobile Gateway
Teamware Office
UW IMAP
wodImapServer ActiveX component
Zarafa Collaboration Platform
Zimbra Collaboration Server
Zoho Mail
Services that support IMAP IDLE
FastMail
