Skip to main content

Programatically extracting quoted reply from an email

When files are uploaded to our cloud file server, we wanted to send notification email per file with its own unique email address. I will discuss how to have so many unique email address without creating a user on mail server for each file and scale out the solution in some later blog. People can just hit reply button on the generated notification email and comment on the uploaded file. When reply email reaches back the server we want to extract the comment that user added after stripping out the quoted reply form the mail client and add the clean comment to file. Seems like an easy problem isnt it, but unfortunately there is no easy way to detect the quoted reply from an incoming email because different mail clients use different way to quote a reply. On top of it quoted reply of html emails are different than plain text quoted replies.
  1. Angle Brackets "> xxx zzz"
  2. "---Original Message---"
  3. "On such-and-such day, so-and-so wrote:"
  4. html email reply in thunderbird uses blockquote tags.
  5. yahoo/hotmail uses some div tags
Got an brilliant idea from someone to add a hash marker in the outbound notification email  so that when it comes back we can strip the text after that marker. Then I found other sites are already doing this like redmine or issueburner already does that. These guys add a marker text in outbound email like below

##### Please do not write below this line #####
Hi kalpesh,

The issue has been updated.

Updated by:     Kris Katta
Comment added:     this is a test comment
Kris Katta's Reply..

This is a test reply

To track the status of your request and set up a profile for yourself, follow the link below:

Now all that is left to extract the mail header so using some regex you can strip that. I  have handled thunderbird and outlook and will soon add yahoo/hotmail. Below is some sample code.

 * @author kpatel
public class QuotedReplyExtractor {
    public static final String 
REPLY_MARKER = "--- Please reply ABOVE THIS LINE to comment on this file ---";

    private static final List patterns = new ArrayList();
    static {
                .add(Pattern.compile(".*on.*?wrote:", Pattern.CASE_INSENSITIVE));

    public String stripQuotedReply(String comment) {
        int startIndex = comment.indexOf(REPLY_MARKER);
        if (startIndex > 0) {
            comment = comment.substring(0, startIndex);
        for (Pattern pattern : patterns) {
            Matcher matcher = pattern.matcher(comment);
            if (matcher.find()) {
                startIndex = matcher.start();
                comment = comment.substring(0, startIndex);
        return comment;



Post a Comment

Popular posts from this blog

RabbitMQ java clients for beginners

Here is a sample of a consumer and producer example for RabbitMQ. The steps are
Download ErlangDownload Rabbit MQ ServerDownload Rabbit MQ Java client jarsCompile and run the below two class and you are done.
This sample create a Durable Exchange, Queue and a Message. You will have to start the consumer first before you start the for the first time.

For more information on AMQP, Exchanges, Queues, read this excellent tutorial
import com.rabbitmq.client.Connection; import com.rabbitmq.client.Channel; import com.rabbitmq.client.*; public class RabbitMQProducer { public static void main(String []args) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setUsername("guest"); factory.setPassword("guest"); factory.setVirtualHost("/"); factory.setHost(""); factory.setPort(5672); Conne…

Logging to Graphite monitoring tool from java

We use Graphite as a tool for monitoring some stats and watch trends. A requirement is to monitor impact of new releases as build is deployed to app nodes to see if things like
1) Has the memcache usage increased.
2) Has the no of Java exceptions went up.
3) Is the app using more tomcat threads.
Here is a screenshot

We changed the installer to log a deploy event when a new build is deployed. I wrote a simple spring bean to log graphite events using java. Logging to graphite is easy, all you need to do is open a socket and send lines of events.
import org.slf4j.Logger;import org.slf4j.LoggerFactory; import; import; import; import java.util.HashMap; import java.util.Map; public class GraphiteLogger { private static final Logger logger = LoggerFactory.getLogger(GraphiteLogger.class); private String graphiteHost; private int graphitePort; public String getGraphiteHost() { return graphiteHost; } public void setGraphite…

What a rocky start to labor day weekend

Woke up by earthquake at 7:00 AM in morning and then couldn't get to sleep. I took a bath, made my tea and started checking emails and saw that after last night deployment three storage node out of 100s of nodes were running into Full GC. What was special about the 3 nodes was that each one was in a different Data centre but it was named same app02.  This got me curious I asked the node to be taken out of rotation and take a heap dump.  Yesterday night a new release has happened and I had upgraded spymemcached library version as new relic now natively supports instrumentation on it so it was a suspect. And the hunch was a bullseye, the heap dump clearly showed it taking 1.3G and full GCs were taking 6 sec but not claiming anything.

I have a quartz job in each jvm that takes a thread dump every 5 minutes and saves last 300 of them, checking few of them quickly showed a common thread among all 3 data centres. It seems there was a long running job that was trying to replicate pending…