JavaMail API Notes

JavaMail(TM) API

Welcome to the JavaMail API implementation.

Please refer to CHANGES.txt for a list of the changes since the previous release.

Please see the FAQ at https://javaee.github.io/javamail/FAQ

Protocol Providers

The JavaMail API jar file "mail.jar" includes the full JavaMail API implementation and the Sun protocol providers - IMAP, SMTP, and POP3. The simplest way to use the JavaMail API is to just use the mail.jar file and ignore the other jar files in this package.

In some cases it may be desirable to minimize the size of the JavaMail API code used by an application (e.g., when downloading with an applet). In this case you might want to include the "mailapi.jar" file, which includes *no* protocol providers, along with just the jar file for the protocol provider you need. For example, an applet that only needs to send mail could use the "mailapi.jar" file and the "smtp.jar" file.

An important note when using the separate protocol provider jar files:
You can't mix and match the Sun protocol providers between different releases of the JavaMail API. The Sun protocol providers depend on implementation-specific utility APIs within the mailapi.jar file. (Third party protocol providers that don't depend on these APIs should work fine.)

NOTE:The Sun protocol provider documentation is available in javadoc format, see https://docs.microsoft.com/en-us/ in the directory where you extracted the JavaMail API zip file. This documentation describes how to use features of the Sun protocol providers to directly access some features of the SMTP, IMAP, and POP3 protocols that are not otherwise supported by the standard JavaMail API.

Gmail IMAP Provider

This release includes an EXPERIMENTAL Gmail IMAP provider. Normal use of Gmail is handled by the standard "imap" protocol provider, but the new "gimap" protocol provider supports additional Gmail-specific non-standard features. See the javadocs for the com.sun.mail.gimap package for details. Note that the gimap.jar file needs to be added to your CLASSPATH to use this new provider.

SASL Support

On systems that support the Java SASL API (javax.security.sasl, JSR-28), such as J2SE 5.0 and later, the IMAP provider can use the SASL API to find an appropriate authentication mechanism. The SASL API also allows you to plug in support for custom authentication mechanisms. See The Java SASL API Programming and Deployment Guide at https://docs.oracle.com/javase/6/docs/technotes/guides/security/sasl/sasl-refguide.html for details on developing custom SASL mechanisms. See the javadocs for the com.sun.mail.imap package for the properties required to enable and configure SASL support.

DSN Support

This release of JavaMail includes EXPERIMENTAL support for creating and parsing Delivery Status Notifications, as defined by RFC 3462 and RFC 3464. To make use of this support you need to include dsn.jar in your CLASSPATH along with mail.jar. See the javadocs for the com.sun.mail.dsn package for more details.

The DSN package also provides support for creating and parsing Message Disposition Notifications, as defined by RFC 3798.

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.

NTLM Support

This release of JavaMail includes EXPERIMENTAL support for the Microsoft NTLM authentication mechanism used by Exchange. See the file NTLMNOTES.txt for details.

OSGi Support

The JavaMail jar files are now OSGi bundles. Please let us know of any problems using JavaMail with OSGi.

How to submit bug reports

If you've found a bug, or if you just need help figuring out how to use the JavaMail API, please try to include the following information in your message to us:

  • a program or code snippet that shows the problem
  • the platform you are using
  • the mail server (vendor name, version number) you are using
  • your environment variable settings
  • a stack trace, if appropriate
  • a protocol trace, after turning on session debugging, if appropriate

Most of the problems reported to us fail to include enough of the above information to allow us to diagnose your problem. It will save you and us time if you include this information in your first message to us.

By far the most common problems we see are:

Your problem: Something doesn't work right when talking to my mail server.
Our response: Turn on session debugging and send us the protocol trace. See the demo program documentation for how to turn on session debugging for the demo programs. In your own program, call "session.setDebug(true);".
Your problem: javax.mail or javax.activation classes not found when compiling.
Our response: You didn't set CLASSPATH correctly to find mail.jar and activation.jar. See README.txt.
Your problem: NoSuchProviderException - No such provider for rfc822.
Our response: You unjar'ed mail.jar. Don't.
Your problem: How do I create a message with an attachment?
Our response: Create a message with a MimeMultipart content. See the sendfile.html and msgmultisendsample.java demo programs.

Please check the FAQ at https://javaee.github.io/javamail/FAQ before submitting bug reports.

Send your bug reports to:javamail_ww@oracle.com

A list of the known limitations, bugs, issues:

  1. This version of JavaMail will only work in applets when using the Java(TM) Plug-in (http://www.oracle.com/technetwork/java/index-jsp-141438.html), which is part of the current Java Runtime Environment (JRE) available from Oracle at: https://www.oracle.com/java/technologies/javase-downloads.html
  2. Internationalization. Parameter encoding in MIME headers, as specified by RFC2231, *has* been implemented. Note that this covers only certain special cases not covered by the MIME specification. MIME specifies encoding of text in the Subject and address headers, and JavaMail fully supports such encoding. Most mailers don't support RFC2231.
    To enable RFC2231 support in parameter lists, set the System properties mail.mime.encodeparameters and mail.mime.decodeparameters to "true".
  3. We've received reports of IMAP authentication failures on the Microsoft Exchange Server 5.5, enterprise edition. This is due to a bug in the Microsoft server and the "Service Pack 1 for Exchange Server 5.5" apparently fixes this server bug. The service pack can be downloaded from the Microsoft website.
  4. Due to a problem in the Microsoft Exchange IMAP server, insufficient number of bytes may be retrieved when reading big messages. There are two ways to workaround this Exchange bug:
    1. The Exchange IMAP server provides a configuration option called "fast message retrieval" to the UI. Simply go to the site, server or recipient, click on the "IMAP4" tab, and one of the check boxes is "enable fast message retrieval". Turn it off and the octet counts will be exact. This is fully described at https://support.microsoft.com/en-us
    2. Set the "mail.imap.partialfetch" property to false. You'll have to set this property in the Properties object that you provide to your Session.
  5. Certain IMAP servers do not implement the IMAP Partial FETCH functionality properly. This problem typically manifests as corrupt email attachments when downloading large messages from the IMAP server. To workaround this server bug, set the "mail.imap.partialfetch" property to false. You'll have to set this property in the Properties object that you provide to your Session.

Servers tested with:

The IMAP implementation works with IMAP4 and IMAP4rev1 servers.

The current release has been tested with:

  • Oracle Beehive
  • Sun Java System Messaging Server version 7.0
  • UW IMAP4 server version 2003.339
  • Cyrus IMAP4 server version 1.6.19

Previous releases have been tested with:

  • Sun Java System Messaging Server version 5.2
  • Sun Java System Messaging Server version 6.3
  • Sun Internet Mail Server version 2.0, 3.2, and 4.0
  • Netscape Messaging Server version 3.01 and 4.1
  • Microsoft Exchange
  • Microsoft MCIS Mail Server
  • Lotus Notes
  • Software.com IMAP server
  • Qualcomm Worldmail

The current release of the SMTP implementation has been tested with:

  • Sendmail version 8.13.8
  • Oracle Beehive
  • Sun Java System Messaging Server version 7.0

Previous releases have been tested with:

  • Sendmail version 8.6 and 8.9.1
  • Sun Java System Messaging Server version 5.2
  • Sun Java System Messaging Server version 5.2
  • Sun Internet Mail Server version 3.2 and 4.0
  • Netscape Messaging Server version 3.01 and 4.1
  • Microsoft Exchange
  • Microsoft MCIS Mail Server
  • Qualcomm Worldmail


How to give feedback

Please send your feedback to this email-address: javamail_ww@oracle.com

Check out our website at:
https://www.oracle.com/technetwork/java/javamail/index.html

You can also find help in the JavaMail forum:
https://community.oracle.com/community/groundbreakers/java/java-ee-java-enterprise-edition/javamail