Using Javamail to connect to Gmail smtp server ignores specified port and tries to use 25

Question

I m trying to use javamail in a groovy script to send out an email via gmail  I ve looked many places online and have been unable to get it working thus far  The error I m getting when running my script is   DEBUG SMTP  useEhlo true  useAuth false DEBUG SMTP  trying to connect to host  smtp gmail com   port 25  isSSL false Caught  javax mail SendFailedException  Send failure  javax mail MessagingException  Could not connect to SMTP host  smtp gmail com  port  25  javax net ssl SSLException  Unrecognized SSL message  plaintext connection      It appears to be trying to use port 25 even though I ve specified that it should use port 587  Does anyone know what could be causing this problem  I ve used telnet to connect to the smtp server on port 587  and thunderbird uses port 587 with STARTTLS security and is able to successfully send mail using the smtp server  This tells me that it is not a blocked port or connectivity issue  Here is the code I m using to try and send the email   import javax mail   import javax mail internet    private class SMTPAuthenticator extends Authenticator       public PasswordAuthentication getPasswordAuthentication                 return new PasswordAuthentication  email gmail com    password             def  d email    email gmail com           d password    password           d host    smtp gmail com           d port     587     465 587         m to    email gmail com           m subject    Testing           m text    This is a test    def props   new Properties   props put  mail smtp user   d email  props put  mail smtp host   d host  props put  mail smtp port   d port  props put  mail smtp starttls enable   true   props put  mail smtp debug    true    props put  mail smtp auth    true   props put  mail smtp socketFactory port   d port  props put  mail smtp socketFactory class    javax net ssl SSLSocketFactory   props put  mail smtp socketFactory fallback    false    def auth   new SMTPAuthenticator   def session   Session getInstance props  auth  session setDebug true    def msg   new MimeMessage session  msg setText m text  msg setSubject m subject  msg setFrom new InternetAddress d email   msg addRecipient Message RecipientType TO  new InternetAddress m to   Transport send msg    Any help would be greatly appreciated  Thanks in advance   -Bryan

User · Accepted Answer

In Java you would do something similar to:

Transport transport = session.getTransport("smtps");
transport.connect (smtp_host, smtp_port, smtp_username, smtp_password);
transport.sendMessage(msg, msg.getAllRecipients());
transport.close();

Note 'smtpS' protocol. Also socketFactory properties is no longer necessary in modern JVMs but you might need to set 'mail.smtps.auth' and 'mail.smtps.starttls.enable' to 'true' for Gmail. 'mail.smtps.debug' could be helpful too.

User · Answer

For anyone looking for a full solution  I got this working with the following code based on maximdim s answer   import javax mail   import javax mail internet    private class SMTPAuthenticator extends Authenticator       public PasswordAuthentication getPasswordAuthentication                 return new PasswordAuthentication  email gmail com    test1234             def  d email    email gmail com           d uname    email           d password    password           d host    smtp gmail com           d port     465     465 587         m to    testepscript gmail com           m subject    Testing           m text    Hey  this is the testing email    def props   new Properties   props put  mail smtp user   d email  props put  mail smtp host   d host  props put  mail smtp port   d port  props put  mail smtp starttls enable   true   props put  mail smtp debug    true    props put  mail smtp auth    true   props put  mail smtp socketFactory port   d port  props put  mail smtp socketFactory class    javax net ssl SSLSocketFactory   props put  mail smtp socketFactory fallback    false    def auth   new SMTPAuthenticator   def session   Session getInstance props  auth  session setDebug true    def msg   new MimeMessage session  msg setText m text  msg setSubject m subject  msg setFrom new InternetAddress d email   msg addRecipient Message RecipientType TO  new InternetAddress m to    Transport transport   session getTransport  smtps    transport connect d host  465  d uname  d password   transport sendMessage msg  msg getAllRecipients     transport close

User · Answer

Maybe useful for anyone else running into this issue  When setting the port on the properties   props put  mail smtp port   smtpPort       make sure to use a string object  Using a numeric  ie Long  object will cause this statement to seemingly have no effect

[java] Using Javamail to connect to Gmail smtp server ignores specified port and tries to use 25

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