Hi everyone. I installed ISPConfig3 yesterday on Ubuntu 11.04 64 bit. So far everything is working except that I cannot connect to the smtp server to send emails. I can receive emails and I can send emails throught squirrelmail. When I try to send emails via Mac Mail application or on iPhone, I cannot connect to the smtp server. I have used as url the FQDN of my server and as username I used my email address and the password of my emailaddress. What am I doing wrong?
Code: root@li349-112:~# netstat -tap | grep smtp tcp 0 0 *:smtp *:* LISTEN 7824/master root@li349-112:~# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination fail2ban-courierimaps tcp -- anywhere anywhere multiport dports imaps fail2ban-courierimap tcp -- anywhere anywhere multiport dports imap2 fail2ban-courierpop3s tcp -- anywhere anywhere multiport dports pop3s fail2ban-courierpop3 tcp -- anywhere anywhere multiport dports pop3 fail2ban-pureftpd tcp -- anywhere anywhere multiport dports ftp fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh fail2ban-sasl tcp -- anywhere anywhere multiport dports smtp Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain fail2ban-courierimap (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-courierimaps (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-courierpop3 (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-courierpop3s (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-pureftpd (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-sasl (1 references) target prot opt source destination RETURN all -- anywhere anywhere Chain fail2ban-ssh (1 references) target prot opt source destination RETURN all -- anywhere anywhere
Thats ok, so the problem is most likely not related to your server. Where is the server hosted, in a datacenter or at home / in office behind a dsl line? If the server is hosted behind a dsl line, then it might be that your dsl provider blocks port 25 (which many providers do to prevent spam) or that your firewall or router is not configured to forward traffic on port 25 to your server.
The server is hosted in a datacenter. I can send mails from the webmail, but not from my home. I think my ISP is blocking port 25 to the outside world. How can I configure the SMTP server so that I can connect to it on another port than port 25?
No customer of your ISP would be able to send emails if your ISP does this, so I don't think that is the problem. Can you try to completely switch off the firewall on your server for testing purposes?
I think I got it right. My ISP is Telenet from Belgium and they only allow traffic outgoing on port 25 to their own mailservers. I was able to contact the smtp server from Gmail on port 587, but I don't know how to set this up on my own SMTP server inside ISPConfig.
