{"id":13479,"date":"2014-05-14T14:45:51","date_gmt":"2014-05-14T09:15:51","guid":{"rendered":"https:\/\/2thenew.online\/blog\/?p=13479"},"modified":"2016-12-19T14:54:40","modified_gmt":"2016-12-19T09:24:40","slug":"receive-email-using-subethasmtp-the-local-smtp-server","status":"publish","type":"post","link":"https:\/\/2thenew.online\/blog\/receive-email-using-subethasmtp-the-local-smtp-server\/","title":{"rendered":"Receive Email using SubEthaSMTP (The local SMTP server)."},"content":{"rendered":"

In my Grails app, I came across a requirement of setting up an SMTP server for receiving mails and extracting their content. After exploring a lot I found SubEthaSMTP to be the most suitable. SubEthaSMTP<\/a> lets your application receive an SMTP mail very easily. <\/p><\/blockquote>\n

To setup an SMTP server in your application, You need to follow the steps as follows:<\/p>\n

1) Add dependency for the latest (at the time of writing it was 3.1.7) SubEthaSMTP library in the BuildConfig.groovy file.<\/p>\n

[shell]dependencies {
\n runtime "org.subethamail:subethasmtp:3.1.7"
\n}
\n[\/shell]<\/p>\n

2) After adding the library you need to implement two Interfaces, namely MessageHandlerFactory and MessageHandler.<\/p>\n

The MessageHandlerFactory is instantiated for every message to be exchanged in an SMTP conversation which (MessageHandlerFactory) in turn instantiates a new instance of MessageHandler.<\/p>\n

You can implement the MessageHandlerFactory<\/strong> as follows:<\/p>\n

[java]
\nclass MessageHandlerFactoryImpl implements MessageHandlerFactory {<\/p>\n

\t@Override
\n \tMessageHandler create(MessageContext ctx) {
\n \treturn new MessageHandlerImpl(ctx)
\n \t}
\n}
\n[\/java]<\/p>\n

And you can implement the MessageHandler<\/strong> as follows:<\/p>\n

[java]
\n@Log4j
\nclass MessageHandlerImpl implements MessageHandler {
\n MessageContext context<\/p>\n

MessageHandlerImpl() {}<\/p>\n

MessageHandlerImpl(MessageContext context) {
\n this.context = context
\n }<\/p>\n

@Override
\n void from(String from) {
\n log.info "FROM: ${from}"
\n }<\/p>\n

@Override
\n void recipient(String recipient) {
\n log.info "RECIPIENT: ${recipient}"
\n }<\/p>\n

@Override
\n void data(InputStream data) {
\n log.info "DATA"
\n }<\/p>\n

@Override
\n void done() {
\n log.info "DONE"
\n }
\n}
\n[\/java]<\/p>\n

The from()<\/em>, recipient()<\/em> and data()<\/em> methods will be called during each stage of SMTP. Multiple MessageHandler are created if multiple messages are delivered with a single SMTP session.<\/p>\n

3) Run the SmtpServer on your app’s start up.<\/p>\n

[java]
\n SMTPServer smtpServer = new SMTPServer(new MessageHandlerFactoryImpl())<\/p>\n

smtpServer.hostName=<your hostname>
\n smtpServer.port =<some port>
\n smtpServer.start()
\n[\/java]\n<\/ul>\n

After getting your SmtpServer instance running the next thing you need to do is to send email to your app. For this you can use Telnet<\/strong> program or you can configure a messenger like Thunderbird<\/strong> or Kmail<\/strong> to send mail on locally running SMTP server which is localhost<\/strong>.<\/p>\n

The Telnet program can be used to send emails, as shown below (Note: My SMTP server is running on port 25000):<\/p>\n

\"Blog<\/p>\n

\n

Voilla! it worked.<\/p>\n

That’s all you need to run local SMTP server in your app!<\/p>\n

The next milestone is to read content of mail<\/p>\n

Most of the email client send a multipart message. A MultipartMessage<\/strong> is a simple Message<\/strong> object where the Content-Type<\/em> is set to multipart<\/em> and the content body carries a reference to a Multipart object.<\/p>\n

\n You can easily retrieve content from multipart content-typed message using MimeMessage instance. For this you need to include JavaMail API Dsn<\/a> library. You can extract body part from multipart message with MultipartReport instance. You can do this as follows:\n<\/p>\n

[java]
\nSession session = Session.getDefaultInstance(new Properties())<\/p>\n

MimeMessage message = new MimeMessage(session, data)<\/p>\n

if (obj instanceof MimeMultipart) {
\n MultipartReport multipartReport = new MultipartReport(message.dataHandler.dataSource);
\n def parsedText = multipartReport.textBodyPart.inputStream
\n log.info "Body content : ${parsedText}"
\n}
\n[\/java]<\/p>\n

So guys, this is how you can implement your own locally running SMTP server with very less effort!<\/p>\n

\n

Akash Sethi
\nSoftware Engineer
\nIntelliGrape Software Pvt. Ltd.
\nakash@intelligrape.com
\nMy LinkedIn<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

In my Grails app, I came across a requirement of setting up an SMTP server for receiving mails and extracting their content. After exploring a lot I found SubEthaSMTP to be the most suitable. SubEthaSMTP lets your application receive an SMTP mail very easily. To setup an SMTP server in your application, You need to […]<\/p>\n","protected":false},"author":67,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":120,"footnotes":""},"categories":[7],"tags":[1426,4840,4844,1423,1424,1434,1433],"class_list":["post-13479","post","type-post","status-publish","format-standard","hentry","category-grails","tag-email-processing-application","tag-grails","tag-java","tag-smtp","tag-subetha-smtp","tag-subethasmtp","tag-telnet"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t