An IMAP protocol provider for the JavaMail API that provides access to an IMAP message store. Both the IMAP4 and IMAP4rev1 protocols are supported. Refer to RFC 2060 for more information.

The IMAP protocol provider can use SASL (RFC 2222) authentication mechanisms on systems that support the `javax.security.sasl` APIs, such as J2SE 5.0. In addition to the SASL mechanisms that are built into the SASL implementation, users can also provide additional SASL mechanisms of their own design to support custom authentication schemes. See the Java SASL API Programming and Deployment Guide for details. Note that the current implementation doesn't support SASL mechanisms that provide their own integrity or confidentiality layer.

A connected IMAPStore maintains a pool of IMAP protocol objects for use in communicating with the IMAP server. The IMAPStore will create the initial AUTHENTICATED connection and seed the pool with this connection. As folders are opened and new IMAP protocol objects are needed, the IMAPStore will provide them from the connection pool, or create them if none are available. When a folder is closed, its IMAP protocol object is returned to the connection pool if the pool is not over capacity.

A mechanism is provided for timing out idle connection pool IMAP protocol objects. Timed out connections are closed and removed (pruned) from the connection pool.

The connected IMAPStore object may or may not maintain a separate IMAP protocol object that provides the store a dedicated connection to the IMAP server. This is provided mainly for compatibility with previous implementations of the IMAP protocol provider.

The IMAP protocol provider supports the following properties, which may be set in the JavaMail `Session` object. The properties are always set as strings; the Type column describes how the string is interpreted. For example, use

    	props.put("mail.imap.port", "888");

to set the `mail.imap.port` property, which is of type int.

Note that if you're using the "imaps" protocol to access IMAP over SSL, all the properties would be named "mail.imaps.*".

Name | Type | Description
--- | --- | ---
mail.imap.user | String | Default user name for IMAP.
mail.imap.host | String | The IMAP server to connect to.
mail.imap.port | int | The IMAP server port to connect to, if the connect() method doesn't explicitly specify one. Defaults to 143.
mail.imap.partialfetch | boolean | Controls whether the IMAP partial-fetch capability should be used. Defaults to true.
mail.imap.fetchsize | int | Partial fetch size in bytes. Defaults to 16K.
mail.imap.connectiontimeout | int | Socket connection timeout value in milliseconds. Default is infinite timeout.
mail.imap.timeout | int | Socket I/O timeout value in milliseconds. Default is infinite timeout.
mail.imap.statuscachetimeout | int | Timeout value in milliseconds for cache of STATUS command response. Default is 1000 (1 second). Zero disables cache.

mail.imap.appendbuffersize

int

Maximum size of a message to buffer in memory when appending to an IMAP folder. If not set, or set to -1, there is no maximum and all messages are buffered. If set to 0, no messages are buffered. If set to (e.g.) 8192, messages of 8K bytes or less are buffered, larger messages are not buffered. Buffering saves cpu time at the expense of short term memory usage. If you commonly append very large messages to IMAP mailboxes you might want to set this to a moderate value (1M or less).

mail.imap.connectionpoolsize | int | Maximum number of available connections in the connection pool. Default is 1.
mail.imap.connectionpooltimeout | int | Timeout value in milliseconds for connection pool connections. Default is 45000 (45 seconds).
mail.imap.separatestoreconnection | boolean | Flag to indicate whether to use a dedicated store connection for store commands. Default is false.

mail.imap.allowreadonlyselect

boolean

If false, attempts to open a folder read/write will fail if the SELECT command succeeds but indicates that the folder is READ-ONLY. This sometimes indicates that the folder contents can'tbe changed, but the flags are per-user and can be changed, such as might be the case for public shared folders. If true, such open attempts will succeed, allowing the flags to be changed. The `getMode` method on the `Folder` object will return `Folder.READ_ONLY` in this case even though the `open` method specified `Folder.READ_WRITE`. Default is false.

mail.imap.auth.login.disable | boolean | If true, prevents use of the non-standard `AUTHENTICATE LOGIN` command, instead using the plain `LOGIN` command. Default is false.
mail.imap.auth.plain.disable | boolean | If true, prevents use of the `AUTHENTICATE PLAIN` command. Default is false.
mail.imap.auth.ntlm.disable | boolean | If true, prevents use of the `AUTHENTICATE NTLM` command. Default is false.
mail.imap.proxyauth.user | String | If the server supports the PROXYAUTH extension, this property specifies the name of the user to act as. Authenticate to the server using the administrator's credentials. After authentication, the IMAP provider will issue the `PROXYAUTH` command with the user name specified in this property.
mail.imap.starttls.enable | boolean | If true, enables the use of the `STARTTLS` command (if supported by the server) to switch the connection to a TLS-protected connection before issuing any login commands. Note that an appropriate trust store must configured so that the client will trust the server's certificate. This feature only works on J2SE 1.4 and newer systems. Default is false.
mail.imap.starttls.required | boolean | If true, requires the use of the `STARTTLS` command. If the server doesn't support the STARTTLS command, or the command fails, the connect method will fail. Defaults to false.
mail.imap.localaddress | String | Local address (host name) to bind to when creating the IMAP socket. Defaults to the address picked by the Socket class. Should not normally need to be set, but useful with multi-homed hosts where it's important to pick a particular local address to bind to.
mail.imap.localport | int | Local port number to bind to when creating the IMAP socket. Defaults to the port number picked by the Socket class.
mail.imap.sasl.enable | boolean | If set to true, attempt to use the javax.security.sasl package to choose an authentication mechanism for login. Defaults to false.
mail.imap.sasl.mechanisms | String | A space or comma separated list of SASL mechanism names to try to use.
mail.imap.sasl.authorizationid | String | The authorization ID to use in the SASL authentication. If not set, the authentication ID (user name) is used.
mail.imap.sasl.realm | String | The realm to use with SASL authentication mechanisms that require a realm, such as DIGEST-MD5.
mail.imap.sasl. xgwtrustedapphack.enable | boolean | If set to true, enables a workaround for a bug in the Novell Groupwise XGWTRUSTEDAPP SASL mechanism, when that mechanism is being used. Defaults to true.
mail.imap.auth.ntlm.domain | String | The NTLM authentication domain.
mail.imap.auth.ntlm.flags | int | NTLM protocol-specific flags. See http://curl.haxx.se/rfc/ntlm.html#theNtlmFlags for details.
mail.imap.socketFactory | SocketFactory | If set to a class that implements the `javax.net.SocketFactory` interface, this class will be used to create IMAP sockets. Note that this is an instance of a class, not a name, and must be set using the `put` method, not the `setProperty` method.
mail.imap.socketFactory.class | String | If set, specifies the name of a class that implements the `javax.net.SocketFactory` interface. This class will be used to create IMAP sockets.
mail.imap.socketFactory.fallback | boolean | If set to true, failure to create a socket using the specified socket factory class will cause the socket to be created using the `java.net.Socket` class. Defaults to true.
mail.imap.socketFactory.port | int | Specifies the port to connect to when using the specified socket factory. If not set, the default port will be used.
mail.imap.ssl.enable | boolean | If set to true, use SSL to connect and use the SSL port by default. Defaults to false for the "imap" protocol and true for the "imaps" protocol.
mail.imap.ssl.checkserveridentity | boolean | If set to true, check the server identity as specified by RFC 2595. These additional checks based on the content of the server's certificate are intended to prevent man-in-the-middle attacks. Defaults to false.
mail.imap.ssl.trust | String | If set, and a socket factory hasn't been specified, enables use of a {@link com.sun.mail.util.MailSSLSocketFactory MailSSLSocketFactory}. If set to "*", all hosts are trusted. If set to a whitespace separated list of hosts, those hosts are trusted. Otherwise, trust depends on the certificate the server presents.
mail.imap.ssl.socketFactory | SSLSocketFactory | If set to a class that extends the `javax.net.ssl.SSLSocketFactory` class, this class will be used to create IMAP SSL sockets. Note that this is an instance of a class, not a name, and must be set using the `put` method, not the `setProperty` method.
mail.imap.ssl.socketFactory.class | String | If set, specifies the name of a class that extends the `javax.net.ssl.SSLSocketFactory` class. This class will be used to create IMAP SSL sockets.
mail.imap.ssl.socketFactory.port | int | Specifies the port to connect to when using the specified socket factory. If not set, the default port will be used.
mail.imap.ssl.protocols | string | Specifies the SSL protocols that will be enabled for SSL connections. The property value is a whitespace separated list of tokens acceptable to the `javax.net.ssl.SSLSocket.setEnabledProtocols` method.
mail.imap.ssl.ciphersuites | string | Specifies the SSL cipher suites that will be enabled for SSL connections. The property value is a whitespace separated list of tokens acceptable to the `javax.net.ssl.SSLSocket.setEnabledCipherSuites` method.
mail.imap.minidletime | int | Applications typically call the idle method in a loop. If another thread termiantes the IDLE command, it needs a chance to do its work before another IDLE command is issued. The idle method enforces a delay to prevent thrashing between the IDLE command and regular commands. This property sets the delay in milliseconds. If not set, the default is 10 milliseconds.

mail.imap.enableimapevents

boolean

Enable special IMAP-specific events to be delivered to the Store's `ConnectionListener`. If true, unsolicited responses received during the Store's `idle` method will be sent as `ConnectionEvent`s with a type of `IMAPStore.RESPONSE`. The event's message will be the raw IMAP response string. By default, these events are not sent. NOTE: This capability is highly experimental and likely will change in future releases.

mail.imap.folder.class | String | Class name of a subclass of `com.sun.mail.imap.IMAPFolder`. The subclass can be used to provide support for additional IMAP commands. The subclass must have public constructors of the form `public MyIMAPFolder(String fullName, char separator, IMAPStore store, Boolean isNamespace)` and `public MyIMAPFolder(ListInfo li, IMAPStore store)`

In general, applications should not need to use the classes in this package directly. Instead, they should use the APIs defined by `javax.mail` package (and subpackages). Applications should never construct instances of `IMAPStore` or `IMAPFolder` directly. Instead, they should use the `Session` method `getStore` to acquire an appropriate `Store` object, and from that acquire `Folder` objects.

WARNING: The APIs unique to this package should be considered EXPERIMENTAL. They may be changed in the future in ways that are incompatible with applications using the current APIs.