I have an application running on Windows machine. the application related alerts are to be e-mailed to administrator,for which an e-mail needs to be sent by Java program. The SMTP server is configured on a remote Linux machine in network.
The Java Mail program works fine and sends out an email, when run on the Linux machine. However if the same program is run on Windows it fails to connect to the SMTP server.
Note:
Ping to the Linux Machine (having SMTP server) is successful from Remote windows server.
Telnet < SMTP server hostname > 25 fails from remote machine as well from the machine where SMTP is running
Telnet localhost 25 is sucessful from SMTP server (Linux server).
The email by Java program is sucessfull, if run on SMTP server when hostname is specified as localhost.It fails if you give actual hostname.
/etc/hosts file on SMTP server lists 127.0.0.1 localhost.
How can i use the SMTP server to send an email from remote Windows machine?
I can paste the errors coming up on windows machine but the problem is not with the program; its the way the SMTP server is configured. I am new to SMTP so feel free to correct me if i am wrong.
The objective is to send a java e-mail from remote windows machine using the SMTP server on the Linux machine.
Adding the Output of netstat -ant|grep :25 as requested in the comment below:
[root@XXXXXXXXXXX]# netstat -ant | grep :25
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN
tcp 0 0 ::1:25 :::* LISTEN
tcp 0 0 ::ffff:10.207.70.71:1521 ::ffff:10.207.70.71:25481 ESTABLISHED
tcp 0 0 ::ffff:10.207.70.71:25481 ::ffff:10.207.70.71:1521 ESTABLISHED
tcp 0 0 ::ffff:10.207.70.71:25202 ::ffff:10.207.70.71:3001 TIME_WAIT
tcp 0 0 ::ffff:10.207.70.71:25127 ::ffff:10.207.70.71:3001 TIME_WAIT
tcp 0 0 ::ffff:10.207.70.71:25289 ::ffff:10.207.70.71:3001 ESTABLISHED
tcp 0 0 ::1:51432 ::1:25580 ESTABLISHED
tcp 0 0 ::1:25580 ::1:51432 ESTABLISHED
tcp 0 0 ::ffff:10.207.70.71:25233 ::ffff:10.207.70.71:3001 TIME_WAIT
tcp 0 0 ::ffff:10.207.70.71:3001 ::ffff:10.207.70.71:25289 ESTABLISHED
[root@XXXXXXXXXXX]#
Your SMTP server (postfix) accepts incoming SMTP connection only on loopback interface(s)
[IPv4=127.0.0.1 and IPv6=::1].
Make your postfix listen on all available IP interfaces -> in main.cf configuration file restore default setting inet_interfaces = all
http://www.postfix.org/postconf.5.html#inet_interfaces
Why "loopback only" configuration is used?
Limiting SMTP server to accept only local SMTP connections is pretty common default configuration on "workstations". It allows sending emails (e.g. system warnings/notifications) without accepting any incoming spam.