Topic: Isp blocking port 25

[Martin]

I'm currently running v.5.1.2
found out that my ISP blocking port 25, So I have to enter these settings, to get mail.

mail.domaene.dk. IN A x.x.x.x
domaene.dk. IN MX 10 mail.domaene.dk.
domaene.dk. IN MX 20 backup-mx.post.tele.dk.

but in wich file?, and where can I find it? this seem's to be my biggest concern right now.


Read in a earlier message, that it was in rcpthost, but it referred to
obtuse-smtpd, then I read it was in sendmail.cf, well anyway I don't understand.
please help.


Martin

[Confucius]

Martin,

Your ISP is not really blocking port 25, they call this a mail-realy to prevent spamming. My ISP does the exact same. The thing you have to do is on your external DNS server (unless you tweaked E-Smith to provide you with 2 named servers). You simply put these lines you already figured out in the file outside.

I used zoneedit.com to do this for me and I am very satisfied. Till now I didn't notice any drop-outs. But that's up to you.

After you made the settings it takes max. 72 hours before the domain can be reached and an amount of time before your ISP is aware of the changes you made. My ISP reads the DNS stats every 8 hours worldwide so that makes it a total of max. 80 hrs I had to wait before I could start to complain (which was needed, but I hope your ISP is not like mine)
But after that it worked for me very smooth and I don't have to be worried that I ever run an open mail-relay myself. (not really important with e-smith guarding it, it's closed already in a perfect way)

Goodluck,

Harro

[ehud gavron]

Most ISPs block OUTGOING port 25, not incoming, at least in the US  That means that anyone should be able to SEND you mail, but that you should not be able to REPLY without going through your ISP's server.

However, if your particular ISP blocks INCOMING 25, then they will have to relay the mail to you, and they can provide you instructions on how to do it.  Generally this consists of two parts, one of which is an mx record inserted into your DNS zone.


DNS information doesn't take "72 hours" or "80 hours" or whatever other random numbers you want to invent.  DNS isn't a "propagating data" protocol, and it's an automaton, not a radom number generator.  The protocol's a "pull as needed" protocol.  To get servers to "pull" quicker, lower the SOA REFRESH time, and up the SOA SERIAL.  (DNS & Bind by Liu and Abitz is a great resource.)

Ehud

[Martin]

My ISP has blocked INCOMING port 25, so I need to put these settings in somewhere, but where.  Do I call my ISP ? I don't think they'll support my SME box. (only windows) ;(

Thank's
Martin.

[Henrik Andreasen]

Martin wrote:

> I'm currently running v.5.1.2
> found out that my ISP blocking port 25, So I have to enter
> these settings, to get mail.

> mail.domaene.dk. IN A x.x.x.x
> domaene.dk. IN MX 10 mail.domaene.dk.
> domaene.dk. IN MX 20 backup-mx.post.tele.dk.
 
> but in wich file?, and where can I find it? this seem's to be
> my biggest concern right now.

There isn’t any local file, for the 2 lines above.
What you need to do, is enter the above 2 lines, in the MX record on your domain, on the DNS servers that resolves your domain.

If TDC include a subdomain (like CyberCity does (xxx.adsl.dk), then the 2 lines above, is probably already in the MX record on it.
If you don’t have a domain and TDC don’t provide you with a subdomain, you can use a dynamic DNS host (e.g. dyndns.dk) to get one and enter the info into that.


Henrik

[Serge Dutremble]

I have found out that my ISP (Bell Sympatico HSE in Ottawa Canada) blocks outgoing SMTP port (Port 25).

On the sme configuration, you have to specify your ISP SMTP server at the appropriate screen (just read the stuff) instead of leaving the entry blank.

Then, any EMail received from your LAN clients by the SME erver will be forwarded to your ISP SMTP and Email will be sent away properly.

No change is necessary for receiving mail if your DNS MX record (from whoever is your DNS provider for your domain) points to your SME server.

Works for me in my situation.

Not sure if it can help in your case.

Just a thought.

Serge.

[ehud gavron]

Given that your domain name is:
domaene.dk

And your server which accepts mail is
mail.domaene.dk

Then the place that needs to be modified
is on the PRIMARY DNS SERVER for domaene.dk.

I'm guessing (based on nslookup) that the
primary domain server is the first one of
these:

Authoritative answers can be found from:
domaene.dk      nameserver = ns1.netropolis.dk
domaene.dk      nameserver = ns2.netropolis.dk
ns1.netropolis.dk       internet address = 129.142.224.3
ns2.netropolis.dk       internet address = 129.142.224.2

That means you need to contact netropolis, and ask
them in the ZONE FILE FOR DOMAEN.DK to add the MX
records as you suggested.

MAKE SURE you've already communicated with the people
who run
backup-mx.post.tele.dk
and they have agreed to 1) accept mail for domaen.dk,
2) relay mail for domaen.dk to you, and 3) that
THEY are NOT blocked from sending to you...
(I'm assuming they are your ISP).

I'm sorry if any of this seems complicated, but there
are little details to go on...

Cheers,

Ehud
Tucson, USA

[Martin]

Thank's everyone, I think I got it now.

Newbie:
Martin