I can receive emails but I can't send mail

[thepascalboy]

Same issue here.. no firewall..no block.. no antivirus no nothing.. clean server..

Same issue too

Sometimes you need to use the smtp server of your network provider, you can add the next line in /etc/postfix/main.cf

Code:

relayhost = smtp.ziggo.nl

for this example smtp.ziggo.nl is my network provider's smtp server, so when I set this I am only able to send mails with sentora otherwise the are blocking port 25 here. Best thing is to ask your provider. I think you need to use smarthost from your provider.