Hello, I had setup a vps with the CentOS Apache installed. I am facing a problem with postfix, I can send & receive emails without problem but I got the bounced back emails in mail log. For your information, I have the port 25,110,587,993,995 opened on firewall and I also could telnet the host like google, yahoo on port 25. PTR & rDNS also been set and I had checked my IP at mxtoolbar.com, it is not being blacklisted. Below are the info of postconf -n. What could be causing this problem??
Can you check your smtp log there is some configuration error i am trying to send you mail its getting "bad syntax error" have a look-- Trying 220.181.14.146... Connected to mr14146.mail.163.com (220.181.14.146). Escape character is '^]'. 220 163.com Anti-spam GT for Coremail System (163com[20141201]) helo mr14146.mail.163.com 250 OK mail from:[email protected] 500 Error: bad syntax try sending mail from your smtp.. telnet 220.181.14.146 25 use standard command you will come to know by seeing maillog.
Hi, thanks for your feedback. I tried to telnet 220.181.14.146 like what you did, I got the connection timed out as shown in the mail log. But, I able to telnet gmail & localhost without problem.. Any idea why? Thanks.
Weird...I noticed that I able to telnet 220.181.14.146 from my others VPS which one of VPS hosted at same supplier - linode and another VPS hosted at digitalocean. The only one thing different among all the VPS is that this newly setup VPS is on CentOS7 while the rest on CentOS6. Nothing is block from my ISP...
Hi, Till. I had followed the guideline -perfect server on CentOS7, apache. I able to telnet other host like gmail, yahoo without problem. I had disabled the firewall on ISPconfig but still showing the same result.
