i had read some posts around here, and because my ISP is blocking the port 25 because is a volatile ip. I had write to my ISP in order to deblock the port, i got no answer till now, but i have no time; so for outgoing mails i solved the problems by relaying all mails to the ISP email, but now my problem now is how to do the problem with incoming e-mails for all my virtual servers.
I mention that i use:
Kernel and CPU Linux 2.6.18-274.17.1.el5.centos.plus on i686
Webmin version 1.570 Virtualmin version 3.89.gpl GPL
Operating system CentOS Linux 5.7
Thanks in advance.
If you’re ISP is blocking incoming port 25 – there’s unfortunately no way to get email to yoru server. A remote mail server only knows how to send email to your server on port 25.
So, your options here would be to either get your ISP to unblock port 25, or to purchase a server (or VPS) at a location that doesn’t block that port.
ived thinked to something else, but if i change the port in postfix for example 2525 can i be able to receive email in my server (incoming ones)?
and if this is the solution, how can i make postfix bind (work) on that port? and the other server knows to send email on that port?
but if i change the port in postfix for example 2525 can i be able to receive email in my server (incoming ones)?
Email servers will only attempt delivery on port 25, they wouldn’t know to look on port 2525.
Your only options to be able to receive email from mail servers around the Internet would be to either get your ISP to unblock port 25, or to purchase a server (or VPS) at a location that doesn’t block that port.
ok, Thanks a lot for this informations…
There are services out there that provide port forwarding for hosting email servers on an ISP that blocks port 25. The only problem being that if your ISP is blocking that port then your service agreement probably doesn’t allow for hosting servers and they may discontinue your service if they find one.
In that case they’d probably be blocking other standard service ports too, like 80 for HTTP and 21 for FTP. Blocking port 25 is probably more of a security measure against spambots. Systems on dialup IPs are usually not supposed to be hosting a server, but owned by end-users who do not require to receive email directly.
Does your ISP offer a static IP option? It’s possible that they won’t block port 25 for those.
That said, using a dynamic/dialup IP to host a mail server constitutes further potential problems. Such IPs are often blacklisted, and servers to which you try to send mail will refuse it.