Develop Reference

Unable to retrieve emails from Gmail using Java

I am trying to write a simple program in Java, in order to check my mailbox and get whatever email is in the inbox.
I have read various tutorials and watched a video in youtube and I found out that most people do something similar to this
So the I have taken the code found there:
import java.util.Properties;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.NoSuchProviderException;
import javax.mail.Session;
import javax.mail.Store;
public class CheckingMails {
public static void check(String host, String storeType, String user,
String password)
{
try {
//create properties field
Properties properties = new Properties();
properties.put("mail.pop3.host", host);
properties.put("mail.pop3.port", "995");
properties.put("mail.pop3.starttls.enable", "true");
Session emailSession = Session.getDefaultInstance(properties);
//create the POP3 store object and connect with the pop server
Store store = emailSession.getStore("pop3");
store.connect(host, user, password);
//create the folder object and open it
Folder emailFolder = store.getFolder("INBOX");
emailFolder.open(Folder.READ_ONLY);
// retrieve the messages from the folder in an array and print it
Message[] messages = emailFolder.getMessages();
System.out.println("messages.length---" + messages.length);
for (int i = 0, n = messages.length; i < n; i++) {
Message message = messages[i];
System.out.println("---------------------------------");
System.out.println("Email Number " + (i + 1));
System.out.println("Subject: " + message.getSubject());
System.out.println("From: " + message.getFrom()[0]);
System.out.println("Text: " + message.getContent().toString());
}
//close the store and folder objects
emailFolder.close(false);
store.close();
} catch (NoSuchProviderException e) {
e.printStackTrace();
} catch (MessagingException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
String host = "pop.gmail.com";// change accordingly
String mailStoreType = "pop3";
String username = "giannisthedrummer2#gmail.com";// change accordingly
String password = "********";// change accordingly
check(host, mailStoreType, username, password);
}
}
But I can't get my mails. Instead this error appears:
javax.mail.AuthenticationFailedException: EOF on socket
at com.sun.mail.pop3.POP3Store.protocolConnect(POP3Store.java:104)
at javax.mail.Service.connect(Service.java:233)
at javax.mail.Service.connect(Service.java:134)
at CheckingMails.check(CheckingMails.java:29)
at CheckingMails.main(CheckingMails.java:69)
I have enabled the POP and IMAP accesibility features on my email, as well as enabled less secure connections.
I downloaded the necessary .jar files from mail.jar and activation.jar
After looking around a bit, I found out that the issue probably is coming from Google's side, meaning that the authentication is going worng. The password and the name is correct (I have checked that multiple times). I have enabled both IMAP and POP connections and I have allowed less secure connections, but still I get an javax.mail.AuthenticationFailedException error.
Any ideas why is this happening?

You're connecting on the SSL port but not enabling SSL. Follow the Gmail instructions in the JavaMail FAQ. Get rid of the port setting and set mail.pop3.ssl.enable.
And make sure you understand the limitations of pop3 vs. imap.

do below change to your Gmail account to access it from outside
Login to Gmail.
Access the URL as https://www.google.com/settings/security/lesssecureapps
Select "Turn on"

For the people that will struggle in the future in the same way I did:
After applying the suggestion from Bill Shannon, I got another error,which I found out that it was coming due to the fact that I hadn't configure the ssl certificates properly. Since I have little to no clue about those, I was searching around the internet to find
Properties properties = new Properties();
properties.put("mail.imap.host", host);
properties.put("mail.imap.user", user);
properties.setProperty("mail.imap.ssl.enable", "true");
properties.put("mail.imap.ssl.trust", "*");
I changed the pop3 protocol to IMAP, because the later allows me to perform more tasks, but for the sole purpose of retrieving my emails both work in the same way.
The last line, in my understanding will accept any certificate, which probably is not the right way to go about it, but at the moment I don't know which one is the correct one.
Thank you all for your help.
****** It is important that the user, enables the POP3/IMAP connections in their accounts and also turn on the less secure applications, as it was stated previously. ******

Extract Email adresses from .pst file with java-libpst

i have several .pst files and need all the mail-addresses, i sent mails to. The example code of the library allows me to traverse every mail in the file, but i can't find the right getter to extract the mail address of the receiver.
To traverse every mail, i use the code from this site:
https://code.google.com/p/java-libpst/
PSTMessage email = (PSTMessage) folder.getNextChild();
while (email != null) {
printDepth();
System.out.println("Email: " + email.getSubject());
printDepth();
System.out.println("Adress: " + email.getDisplayTo());
email = (PSTMessage) folder.getNextChild();
}
The getDisplayTo() method only displays the receivers names but not their mail addresses.
What getter do i need to use to get the addresses?
Best,
Michael

First method : : available getters
getSenderEmailAddress
getNumberOfRecipients
getRecipient(int)
Second Method : parse the header and collect the email address (a_sHeader is a string)
Session s = Session.getDefaultInstance(new Properties());
InputStream is = new ByteArrayInputStream(a_sHeader.getBytes());
try {
m_message = new MimeMessage(s, is);
m_message.getAllHeaderLines();
for (Enumeration<Header> e = m_message.getAllHeaders(); e.hasMoreElements();) {
Header h = e.nextElement();
// Recipients
if (h.getName().equalsIgnoreCase(getHeaderName(RecipientType.REC_TYPE_TO))) {
m_RecipientsTo = processAddresses(h.getValue());
}
...
}
} catch (MessagingException e1) {
...
}

How to access gmail account via javamail

I try to access email account on a certain email server via "imap" through java mail. I did some research on this. And I find the following code which works for gmail.
import java.io.*;
import javax.mail.*;
import javax.mail.internet.*;
public class DeleteMessageExample {
public static void main (String args[]) throws Exception {
String host = args[0];
String username = args[1];
String password = args[2];
// Get session
Session session = Session.getInstance(
System.getProperties(), null);
// Get the store
Store store = session.getStore("imaps");
store.connect(host, username, password);
// Get folder
Folder folder = store.getFolder("INBOX");
folder.open(Folder.READ_WRITE);
BufferedReader reader = new BufferedReader (
new InputStreamReader(System.in));
// Get directory
Message message[] = folder.getMessages();
for (int i=0, n=message.length; i<n; i++) {
System.out.println(i + ": " + message[i].getFrom()[0]
+ "\t" + message[i].getSubject());
System.out.println("Do you want to delete message? [YES to delete]");
String line = reader.readLine();
// Mark as deleted if appropriate
if ("YES".equals(line)) {
message[i].setFlag(Flags.Flag.DELETED, true);
}
}
// Close connection
folder.close(true);
store.close();
}
}
However, I need to specify the args[0] to be imap.gmail.com args[1] to be usrname, args[2] to be password. And if I replace imap.gmail.com by the ip address 74.125.224.86, it no longer work.
My question is suppose I have an account on yahoo mail, what the hostname I should use?
I tried imap.yahoo.com, mail.yahoo.com and the ip address.
If you know the answer, would you mind also told me what is the regular rule to find out what kind hostname I should use?
Thanks a lot.

Unlike Gmail, Yahoo Mail's IMAP services is not a totally standard IMAP service. You need send some special tokens before you login. You need to modify the JavaMail API in order to connect to Yahoo Mail through IMAP. The latest JavaMail 1.4.4-SNAPSHOT release supports Yahoo Mail as well. You can get it here

JavaMail IMAP over SSL quite slow - Bulk fetching multiple messages

I am currently trying to use JavaMail to get emails from IMAP servers (Gmail and others). Basically, my code works: I indeed can get the headers, body contents and so on. My problem is the following: when working on an IMAP server (no SSL), it basically takes 1-2ms to process a message. When I go on an IMAPS server (hence with SSL, such as Gmail) I reach around 250m/message. I ONLY measure the time when processing the messages (the connection, handshake and such are NOT taken into account).
I know that since this is SSL, the data is encrypted. However, the time for decryption should not be that important, should it?
I have tried setting a higher ServerCacheSize value, a higher connectionpoolsize, but am seriously running out of ideas. Anyone confronted with this problem? Solved it one might hope?
My fear is that the JavaMail API uses a different connection each time it fetches a mail from the IMAPS server (involving the overhead for handshake...). If so, is there a way to override this behavior?
Here is my code (although quite standard) called from the Main() class:
public static int connectTest(String SSL, String user, String pwd, String host) throws IOException,
ProtocolException,
GeneralSecurityException {
Properties props = System.getProperties();
props.setProperty("mail.store.protocol", SSL);
props.setProperty("mail.imaps.ssl.trust", host);
props.setProperty("mail.imaps.connectionpoolsize", "10");
try {
Session session = Session.getDefaultInstance(props, null);
// session.setDebug(true);
Store store = session.getStore(SSL);
store.connect(host, user, pwd);
Folder inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
int numMess = inbox.getMessageCount();
Message[] messages = inbox.getMessages();
for (Message m : messages) {
m.getAllHeaders();
m.getContent();
}
inbox.close(false);
store.close();
return numMess;
} catch (MessagingException e) {
e.printStackTrace();
System.exit(2);
}
return 0;
}
Thanks in advance.

after a lot of work, and assistance from the people at JavaMail, the source of this "slowness" is from the FETCH behavior in the API. Indeed, as pjaol said, we return to the server each time we need info (a header, or message content) for a message.
If FetchProfile allows us to bulk fetch header information, or flags, for many messages, getting contents of multiple messages is NOT directly possible.
Luckily, we can write our own IMAP command to avoid this "limitation" (it was done this way to avoid out of memory errors: fetching every mail in memory in one command can be quite heavy).
Here is my code:
import com.sun.mail.iap.Argument;
import com.sun.mail.iap.ProtocolException;
import com.sun.mail.iap.Response;
import com.sun.mail.imap.IMAPFolder;
import com.sun.mail.imap.protocol.BODY;
import com.sun.mail.imap.protocol.FetchResponse;
import com.sun.mail.imap.protocol.IMAPProtocol;
import com.sun.mail.imap.protocol.UID;
public class CustomProtocolCommand implements IMAPFolder.ProtocolCommand {
/** Index on server of first mail to fetch **/
int start;
/** Index on server of last mail to fetch **/
int end;
public CustomProtocolCommand(int start, int end) {
this.start = start;
this.end = end;
}
#Override
public Object doCommand(IMAPProtocol protocol) throws ProtocolException {
Argument args = new Argument();
args.writeString(Integer.toString(start) + ":" + Integer.toString(end));
args.writeString("BODY[]");
Response[] r = protocol.command("FETCH", args);
Response response = r[r.length - 1];
if (response.isOK()) {
Properties props = new Properties();
props.setProperty("mail.store.protocol", "imap");
props.setProperty("mail.mime.base64.ignoreerrors", "true");
props.setProperty("mail.imap.partialfetch", "false");
props.setProperty("mail.imaps.partialfetch", "false");
Session session = Session.getInstance(props, null);
FetchResponse fetch;
BODY body;
MimeMessage mm;
ByteArrayInputStream is = null;
// last response is only result summary: not contents
for (int i = 0; i < r.length - 1; i++) {
if (r[i] instanceof IMAPResponse) {
fetch = (FetchResponse) r[i];
body = (BODY) fetch.getItem(0);
is = body.getByteArrayInputStream();
try {
mm = new MimeMessage(session, is);
Contents.getContents(mm, i);
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
}
// dispatch remaining untagged responses
protocol.notifyResponseHandlers(r);
protocol.handleResult(response);
return "" + (r.length - 1);
}
}
the getContents(MimeMessage mm, int i) function is a classic function that recursively prints the contents of the message to a file (many examples available on the net).
To avoid out of memory errors, I simply set a maxDocs and maxSize limit (this has been done arbitrarily and can probably be improved!) used as follows:
public int efficientGetContents(IMAPFolder inbox, Message[] messages)
throws MessagingException {
FetchProfile fp = new FetchProfile();
fp.add(FetchProfile.Item.FLAGS);
fp.add(FetchProfile.Item.ENVELOPE);
inbox.fetch(messages, fp);
int index = 0;
int nbMessages = messages.length;
final int maxDoc = 5000;
final long maxSize = 100000000; // 100Mo
// Message numbers limit to fetch
int start;
int end;
while (index < nbMessages) {
start = messages[index].getMessageNumber();
int docs = 0;
int totalSize = 0;
boolean noskip = true; // There are no jumps in the message numbers
// list
boolean notend = true;
// Until we reach one of the limits
while (docs < maxDoc && totalSize < maxSize && noskip && notend) {
docs++;
totalSize += messages[index].getSize();
index++;
if (notend = (index < nbMessages)) {
noskip = (messages[index - 1].getMessageNumber() + 1 == messages[index]
.getMessageNumber());
}
}
end = messages[index - 1].getMessageNumber();
inbox.doCommand(new CustomProtocolCommand(start, end));
System.out.println("Fetching contents for " + start + ":" + end);
System.out.println("Size fetched = " + (totalSize / 1000000)
+ " Mo");
}
return nbMessages;
}
Do not that here I am using message numbers, which is unstable (these change if messages are erased from the server). A better method would be to use UIDs! Then you would change the command from FETCH to UID FETCH.
Hope this helps out!

You need to add a FetchProfile to the inbox before you iterate through the messages.
Message is a lazy loading object, it will return to the server for each message and for each
field that doesn't get provided with the default profile.
e.g.
for (Message message: messages) {
message.getSubject(); //-> goes to the imap server to fetch the subject line
}
If you want to display like an inbox listing of say just From, Subject, Sent, Attachement etc.. you would use something like the following
inbox.open(Folder.READ_ONLY);
Message[] messages = inbox.getMessages(start + 1, total);
FetchProfile fp = new FetchProfile();
fp.add(FetchProfile.Item.ENVELOPE);
fp.add(FetchProfileItem.FLAGS);
fp.add(FetchProfileItem.CONTENT_INFO);
fp.add("X-mailer");
inbox.fetch(messages, fp); // Load the profile of the messages in 1 fetch.
for (Message message: messages) {
message.getSubject(); //Subject is already local, no additional fetch required
}
Hope that helps.

The total time includes the time required in cryptographic operations. The cryptographic operations need a random seeder. There are different random seeding implementations which provide random bits for use in the cryptography. By default, Java uses /dev/urandom and this is specified in your java.security as below:
securerandom.source=file:/dev/urandom
On Windows, java uses Microsoft CryptoAPI seed functionality which usually has no problems. However, on unix and linux, Java, by default uses /dev/random for random seeding. And read operations on /dev/random sometimes block and takes long time to complete. If you are using the *nix platforms then the time spent in this would get counted in the overall time.
Since, I dont know what platform you are using, I can't for sure say that this could be your problem. But if you are, then this could be one of reasons why your operations are taking long time. One of the solution to this could be to use /dev/urandom instead of /dev/random as your random seeder, which does not block. This can be specified with the system property "java.security.egd". For example,
-Djava.security.egd=file:/dev/urandom
Specifying this system property will override the securerandom.source setting in your java.security file. You can give it a try. Hope it helps.

Why do i get this exception?

This method gives the number of emails in the inbox.But it gives me this exception :
javax.mail.MessagingException: Connect failed;
nested exception is:
java.net.ConnectException: Connection timed out: connecterror
-
Session session = Session.getInstance(new Properties());
try {
Store store = session.getStore("pop3");
store.connect("pop.gmail.com" , "username" , "password");
Folder fldr = store.getFolder("INBOX");
fldr.open(Folder.READ_WRITE);
int count = fldr.getMessageCount();
System.out.println(count);
} catch(Exception exc) {
System.out.println(exc + "error");
}

Try this :
Properties props = new Properties();
props.put("mail.pop3.host" , "pop.gmail.com");
props.put("mail.pop3.user" , "username");
// Start SSL connection
props.put("mail.pop3.socketFactory" , 995 );
props.put("mail.pop3.socketFactory.class" , "javax.net.ssl.SSLSocketFactory" );
props.put("mail.pop3.port" , 995);
Session session = Session.getDefaultInstance(props , new Authenticator() {
#Override
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication( "username" , "password");
}
});
try {
Store store = session.getStore("pop3");
store.connect("pop.gmail.com" , "username" , "password");
Folder fldr = store.getFolder("INBOX");
fldr.open(Folder.HOLDS_MESSAGES);
int count = fldr.getMessageCount();
System.out.println(count);
} catch(Exception exc) {
System.out.println(exc + " error");
}
Also visit this question

Probably because the server refuses to connect.
Try connecting from "telnet". Once you can connect at all, then you should be able to connect from your Java program.
Here are some troubleshooting tips:
http://www.anta.net/misc/telnet-troubleshooting/pop.shtml
https://www-304.ibm.com/support/docview.wss?uid=swg21097014
http://support.microsoft.com/kb/885685

Try changing
store.connect("pop.gmail.com" , "username" , "password");
to
store.connect("pop.gmail.com" , 995, "username" , "password");
Disclaimer: I have not tested this.
Gmail requires a secure SSL connection, and maybe javax.mail.Service isn't providing that. I think the more likely explanation, though, is that you're simply not connecting to the right port, so I've explicitly specified the correct port number for Gmail's POP3 service.

Try following a "how to use gmail as an smtp server" tutorial. Google also has a configuration page with all the settings you'll need.