Well I'm stuck now. For some reason Postfix still isn't receiving emails and putting them into user mailboxes. Let me make sure I understand this concept correctly...

Remote Computer Sends An Email via SMTP to their server on Port 25 ... Destination Computer Receives this Email via POP3 on port 110... or am I totally wrong?

If Port 25 is directly involved in my receipt of email, I am going to have a problem because CoX has blocked port 25.

If anyone else has suggestions please post them! All help is very much appreciated

ahh I see.

The DNS changes will not matter since you have primary MX as mail.enigmawebware.com. This just points 110 at the ip number that mail.enigmawebware.com backward resolves to which is ip68-10-164-20.hr.hr.cox.net (68.10.164.20).

Good question, and I think that is exactly how it works.

I know there is a way to change what port smtp runs on in postfix, but I'll need to research it a bit. So don't dispair just yet
Try googling for "smtp port cox" and see what you can come up with.

The problem with incoming mail remains though. You should be able to see some activity when you send an email to that server. I'm not sure what's going on with that just yet. When you can test it locally by IP you should have a better idea.

Nothing in your /var/log/maillog?

Might even do a tcpdump on that interface while you try to send mail to it just to see if packets are actually getting there.

hmmm well my friend who is quite familiar with Linux seems to think that SMTP is essential for PostFix to work properly. I have my doubts, but I took his word on it. He suggested changing smtp under /etc/services so I proceeded to do so and set them to 2525/tcp and 2525/udp. That didn't work so well. On my initial try, I still didn't get the mail in the user's mailbox. Then my ISP started acting crazy and killed my ability to connect to AIM and port 10000 on my server. Which is weird, because I've been using Webmin all day, and I don't see why changing the port for SMTP would effect it, especially in a LAN environment. Though Apache, my CDWServer, SSH, FTP, and VNC are still all working flawlessly. I'm wondering if it is a passing glitch that will kinda fix itself by the time I get to work in the morning. I changed my SMTP port back to the standard 25 just in case that's what caused Webmin to stop working.

I have yet to get a chance to do a tcpdump, but that is definitely a good suggestion. What is the best way to accomplish that? I have also found this quick short briefs about setting up Postfix behind CoX but I am slightly confused by it. I think you all may be able to make more sense out of it than I am and give me instructions on how to get this working... apparently others have accomplished it...

http://archives.neohapsis.com/archiv...3-01/2185.html

http://help.changeip.com/Default.asp?kb=30

I think we are getting really close here and I look forward to this being a guide to other CoX Broadband users experiencing the same kinds of problems

I was able to telnet into port 110 on your mail.enigmawebware.com. I got:
+OK POP3 Prometheus.enigmawebware.com v2001.78rh server ready
So we know that the server is open on that port and ready for you to retrieve mail. Postfix is probably up and running.

I learned something here:
Mail is sent FROM SMTP, TO SMTP. The POP3 110 port is only used to accept requests to retrieve mail. I know it sounds simple, but I hadn't really thought about it before :P

Let's try telnetting from the local machine to send an email. At least you can know then if your server is working.

While you are ssh'd in at work you should be able to try this:

telnet mail.enigmawebware.com 25

helo mycomputername
mail from: <joe@somewhere.com>
rcpt to: <ceo@enigmawebware.com>
data
This is a test email. Yeehaw!
.
rset
quit

(notice the period at the end there, you have to hit CRLF.CRLF to end the data input. Then do rset, and quit.)

This will send you a little test email to that address, and tell you whether or not your smtp is working.

cool eh?

Now if that part is indeed working, we just need to find a way for you to use a different port other than 25 to handle this.

I have been reading and discovered the same truth about SMTP last night/this morning. I know that my internal SMTP service is working because my user accounts, root, CDWServer, and Postfix are all exchanging mail from say root@localhost.localdomain ... postfix is also receiving mail from root and believes that it is postfix@enigmawebware.com. So I think SMTP is working, kindof.

I can't telnet mail.enigmawebware.com 25 because as you probably remember, Port 25 is completely blocked by CoX. So there is no way I can try to access that port from the internet...

Here is what I am in the process of trying, but I may be missing a step, so correct me if I'm wrong. Unfortuanately, it's going to be an hour or so before I can truly test this because the appropriate port(s) are not open on my router at home and I have not yet set up a VPN so I have to get my brother who is at the house now to open them for me (at his convenience).

Here is what I have done... I went into /etc/services and added a new service called smtp2 which operates on port 1054. I did not mess with smtp because it will most likely still be referenced by other internal processes and I don't want to mess those up locally.... maybe it would be okay, but from my experience last night in trying to change the smtp port things started getting weird. Then I went into /etc/postfix/master.cf and changed the line that read smtp .. n .. y (etc) to smtp2. By doing this I am hoping that postfix will use smtp2 on port 1054 therefore bypassing the port blocking.

Sounds like it should work in theory right? There may be other things I have to do, or this might not work at all, I'm not sure yet. I will definitely post an update as soon as my router's ports get opened... in the meantime please post any suggestions you might have!

Yea that should work. I think it's smart to leave the port 25 one alone and add the smtp2.

But it will only work for email clients that set their smtp ports to 1054.
As I understand it, the rest of the world won't be able to send to your machine, but you can send out of it and check mail from it.



I can't think of a way around that.
Anyone else have an idea?

I know that this may seem a little off the wall but...

Could it be possible to set up port forwarding with zoneedit.com (my DNS/Nameserver) so that all incoming requests on Port 25 could then be forwarded to say, port 1054? Also, upon further research I see that CoX actually doesn't list Port 53 (DNS) as blocked, though Apache Virtual Servers doesn't work, so I assumed it was.

So I guess my question now is, would there be any way to forward Port 25 requests to a different port on the DNS level?

I'm fuxz0red. As far as I can tell there is no way to get around the SMTP port block. I guess it's time to start looking for a 3rd party solution. If anyone has any suggestions please let me know.

Even though my particular situation was not resolved, hopefully this can serve as an in depth resource to people having troubles with Postfix.

Well there is a solution after a quick google but like most things costs money, probably other companys provide it too, so google

http://www.changeip.com/dsmtpinfo.asp

I had the exact same problem with my ISP blocking port 25. They bolcked the port in response to the msblast virus and of course they wanted me to upgrade to a Business Account to have the port opened. After being unable to contact the Business Account people for 2 days, the tech person opened the port for me. Yet again we see that pleading, crying, begging, and compliments are all a sys admin person requires to perform their job!