Hello guys, I'm using CentOS 6.4 with ISPConfig 126.96.36.199. My main problem is that the server is not sending out the e-mails. Code: # postqueue -p -Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient------- B1F43425A5 1154 Thu Oct 24 10:21:18 email@example.com (connect to alt4.gmail-smtp-in.l.google.com[188.8.131.52]:25: Connection timed out) firstname.lastname@example.org BD88942589 7029339 Thu Oct 24 09:59:59 email@example.com (connect to server.mysite.com[184.108.40.206]:25: Connection timed out) firstname.lastname@example.org 5C1984259F 1271 Thu Oct 24 10:05:04 email@example.com (connect to alt4.gmail-smtp-in.l.google.com[220.127.116.11]:25: No route to host) firstname.lastname@example.org -- 6868 Kbytes in 3 Requests. I always get "Connection timed out" messages. When i try to telnet a host with port 25: Code: # telnet alt4.gmail-smtp-in.l.google.com 25 Trying 18.104.22.168... telnet: connect to address 22.214.171.124: Connection timed out Trying 2a00:1450:4001:c02::1b... telnet: connect to address 2a00:1450:4001:c02::1b: Network is unreachable Firewall: Code: # iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain fail2ban-SSH (0 references) target prot opt source destination RETURN all -- anywhere anywhere This is a dedicated server rented from a hosting company so i don't think that they are blocking this port (25). I have no idea what's going on. Can you help me figure out what's the problem? Thank you!