Enable SMTP Port 587 on Exim
Most of the ISP block port 25 for outgoing SMTP. To enable Port 587 on exim, add this configuration to Exim’s configuration file.
daemon_smtp_ports = 25 : 587
Alternatively, with latest exim configuration file, uncomment the line below and you might want to remove 465.
# daemon_smtp_ports = 25 : 465 : 587
After that, save your configuration and restart exim service.
Test on Port 587
After exim service has restarted, make a telnet test to port 587
shell> telnet localhost 587
Connected? If yes, it means Exim on SMTP Port 587 is enabled now.