PHP Mail Not Working
 

I've got (2) ISPConfig 3 servers. Server A hosts most domains and all emails. Server B hosts 1 domain, but no email. Server A has a direct IP address, Server B is behind a NAT.

I would like to set it up so Server B can send mail (via SMTP) through Server A.

Right now, I'm getting the following on Server B when I try to send mail through Server A: SMTP Error: Could not connect to SMTP host. Neither servers logs show anything (including running tail -f /var/log/syslog on both servers and watching what happens when I hit "send").

Thoughts

Can you send email from A to B?

Some isp block port 25 to prevent spam from infected computers or spamers.

Try to check your firewall/iptables configuration and try to connect manually to anothers mail servers(from B) with:

Thanks... it does appear port 25 is blocked. However, our ISP itself doesn't block any of our ports (I've had this conversation with them in the past).

Also, both servers are connected to the same router, with nothing in the hardware firewall. If the firewall isn't on the router, where else might I look?

FYI: using http://network-tools.com/ I get a connection (that's rejected because relaying isn't allowed)

What are the outputs of and on server A? Are there any errors in your mail logs (on both servers)?

Still pulling my hair out!
 

Server A:

netstat -tap

iptables -L

/etc/postfix/main.cf
Just looking to get Server B to send through Server A...

Server B is behind a NAT on a Cisco router. All ports open, nothing blocked at the router level.

if you can't get it to work directly, an alternate approach would be to setup a open between those two servers. Then you can route the email though the vpn tunnel hence it uses a different port.

Or you can use alternate ports for smtp... I usually do also free 2500 and 2525 or you could try the submission port (587)

i assume that you are running this from your house, or work. i would check the outside ports to make sure they are open. i have heard that line before yes port 25 is open but the person that you are talking to knows nothing other then what is on the monitor in front of them.

to check your ports you can use this site

http://www.yougetsignal.com/tools/open-ports/

if port 25 is blocked you can use a relay service to send mail out on port 2525


this is how i have to do it sucks having to pay for a service but what are you going to do.

Thanks. Going to http://www.yougetsignal.com/tools/open-ports/ shows port 25 open at Server A.

When I send an email from Server B, though, I'm getting this:

Maybe I should just go enjoy the weather which is abnormally, but fantastically warm, and come back to this Monday...

http://www.infoocean.info/avatar1.jpgCan you send email from A to B?

Ok... so this is what I've got.

A & B won't talk to each other, but I can send from out side (for instance Gmail) to A and B.

Here's the setup:

Cisco Router has a static IP of XXX.XXX.XXX.123
Server A is behind the Cisco router with a static IP XXX.XXX.XXX.122
Server B is behind the Cisco Router with a static IP 192.168.1.252, but NATed to XXX.XXX.XXX.124.

Web services work great on A & B. Email is just fine on A. Email is fine on B. Except B won't talk to A and vice versa.

I can't send mail to A or B. If I try to send from B to A, on server B I get:

Also, nothing shows in the logs on Server A when sending from B to A.

When I send from A to B, on server A I get:

and on Server B:

Originally, I was trying to get a web site on Server B to use SMTP to connect to Server A to send emails, but nothing was working. As an alternative, I created some accounts on Server B to send to the Server A accounts, but those weren't working, either.

There is something with how things are configured that keeps A and B from talking to each other on Port 25 (or 587)... but both can talk to the rest of the world.