Port 25 blocked, still anything to do?

Hi:

I use RoadRunner to host my site, and of course, they blocked port 25. Now I've been reading up on this big time. Currently, I use this:

mail.mydomain.com

for the pop host, but for the SMTP, I use my ISP's SMTP server. I was wondering, is there a way I can make it so I can have, something like:

smtp.mydomain.com

like change the port to a higher port? I read a thread and you said to signup for a service. First off, does anyone know of a "free" smtp service? And two, if there's no free ones, is there anything else I can do? I really want to be able to have something like:

mail.mydomain.com for my pop server and
smtp.mydomain.com for my smtp server.

Thanks for any light you can shed on this topic!!!

Ken Cooper

if you use sendmail you should be able to change the default port to something other than 25 and just set your client to use that port... should work.

I use qmail. Do any of you know if you can for qmail? I'll try to look in the docs online in the mean time, but I'd appreciate if someone knows to tell me. Thanks for your help!!!

Ken Cooper

LOOK DOWN ... there a number of posts similar to this that are referenced.

Unfortunately, you will find that a MAIL REFLECTOR service will be required to accept mail on port 25 and then forward it to you.

Your Problem
Internet -> Mail -> || Blocked Port 25

Mail Reflector
Internet -> Mail -> Recieved on Port 25 of Mail Reflector -> forwarded to YOUR Domain on alt port 2525 -> you have Mail

So basically you need a Server that can accept mail on port 25 and then send it to you on a differnet (non-blocked) port. You will most likely have to pay for a Mail Reflector.

If you want qmail to listen on a different port besides 25, just look in your /var/qmail/supervise/qmail-smtpd/run file. In there, you should see "smtp" or "25" somewhere in the file. Just change that to the port you'd like to use.

Use netstat -nap | grep LISTEN to see if the service is listening on the correct port. You should not need to restart qmail, since the qmail-smtpd/run file is read everytime someone connects to it.

Of course, you'll also need to forward that port from your router to your mail server. You may also need to allow the new port on your firewall (if you're using iptables or something).

Hi:

Thanks for that piece of information. That will work just fine. The last question I have for you is, is there a good port that I should use? I read somewhere I should use I high # port, so it doesn't conflict with other ports. Could someone give me a port that I could use, that won't interfere? And two, how would I add this port in iptables? I had trouble adding all the other ports to it. I know how to change it on the router though. Thanks again for ALL your help!!!!!

Edit: The file of mine looks something like this:



see where it says 0 smtp

do I change either the 0 or smtp with the port number? I saw online, someone used the port 2525. So, should it look like 2525 smtp, or 0 2525? Or is that not the right place? And two, after I do that, I restarted the server, and I added the 2525 to my router, but how do I add it to the iptables? Thanks for the help you can give me!

Ken Cooper

You should change the "smtp" to whatever port number you want to use. So you can change that area to look like "0 2525" and that'll work.

Just do a quick google search for port 2525 and see what turns up. If you find that there is some program that typically runs on 2525 and this program is something you might be interested in running on your server someday, then maybe you should pick another port number. But if nothing in particular seems to be used for 2525, or if there is an off-the-wall program that uses 2525 that you dont' care about, then I'd say go for it.

When you make the change, you shouldn't need to restart anything. But if it makes you feel better, you can restart qmail with "qmailctl restart".

You may not need to mess with iptables if you're not using it. Just run "iptables -L" and see if you have a bunch of rules in there. If the output shows something like what I'm showing below, then you don't need to worry about it.

I did what you said, and on my email program, I put my SMTP server as mail.mydomain.com, with port 2525. When I hit the "send" button on an email, it said the SMTP server couldn't connect. I changed it to 0 2525, and added the port to the firewall, but I think it might be the firewall/iptables. Does anyone know how I can add/accept the port 2525 to my linux firewall? Thanks!!!

I tried that program from sourceforge called "portfwd". YOu basically install it, create a *.cfg file, and basically, I told it to foward port 25 to 2500. Saved it, and tried it on a mail program, and it didn't work. Any ideas?

Have you tried running "iptables -L"? We need to know if you have iptables rules defined.

The last part of your run file should look like this...

exec /usr/local/bin/softlimit -m 2000000 \
/usr/local/bin/tcpserver -v -R -l "$LOCAL" -x /etc/tcp.smtp.cdb -c
"$MAXSMTPD" \
-u "$QMAILDUID" -g "$NOFILESGID" 0 2525 /var/qmail/bin/qmail-smtpd
2>&1

Are you using some forwarding service like zoneedit.com?

Do you know if you're allowed to run servers on your internet account?

Maybe consider changing that port to 20000 or some other 5-digit port number. You'll need to forward this from your router to your server also.

You may want to consider using nmap to find out what ports are open. But the easiest thing to do is simply call your isp and as what port numbers are being blocked. They will probably not give you very many answers, since all these tech people assume their users are morons, so you'll need to ask very pointed questions, like "Is port number 2525 closed?" You don't need to tell them what you're trying to do. You can simply say you've got a program you installed that wants to use 2525 and you're wondering if its blocked.

Also, when you call them, you may want to ask if they have smtp servers you can use to relay. These are becoming a thing of the past since they are a security nightmare becuase all of their users are likely trying to exploit them, but if they happen to have some, this would make it easier. You could use their upstream mail servers to relay mail for your server.

Basically these are mail servers on their network that will accept and send mail for all their customers. It's easy to use the /var/qmail/control/smtproutes file to send all outgoing mail to another system for processing. (i.e. theirs)

Right now, I can't even accept mail now, because I think I messed up something when editing the page. I also have some other junk I want to clean out, so I think I'm just going to totally reinstall Linux altogether. Of course backup all my files/mysql data, then start over. I just don't get why it won't work? I'm pretty sure the port 2525 isn't blocked, or anything on. I went on the netstat -nap | grep LISTEN, and it didn't say anything about qmail, or qmailctl. When I did iptables -L, it just showed a bunch of stuff, I know that's quite vague, but it said accept and tcp a few times. BTW, I'm NOT using a forwarding service, like zoneedit.com. And also, my ISP will NOT unblock port 25 for me, so I'll just have to use port 2525, or something like that. Any other ideas? Well, if you were to do this, change the port, restart the server, would it just work, or would you do something else, like with the linux firewall, or a hosts file maybe? I don't know. Thanks for any additional help you can give me!!!!!!

Once again...IF YOUR ISP BLOCKS PORT 25 >>> YOU NEED A REDIRECTOR SERVICE.

from DNSEXIT.COM I'm Not just making this UP to torment YOU. YOUR going to need to PAY someone to redirect your email to your server.
Change the PORTS all you want...PORT 25 is the default PORT that ALL mail is routed on. Changing your ports to 2525 is part of the process of a workaround. You cannot recieve email by just changing the port and hoping for the best...Someone has to sent the Port 25 mail to your new PORT in order for it to work.