Port 25 not listening

S

Shmoo

After more than a year, I suddenly can't send emails. Telneting doesn't work,
and it's not in the list of listening ports. This started after I adjusted my
wireless router to allow a friend on (where Ihad to change my Encryption
setting), but it's related to my computer, not the router, as it's still
happening on a different network, and others can send/telnet. Are there
settings that could have changed? I tried turning off the MS Firewall,
uninstalling AVG, adding an exception to the firewall for port 25 (both tcp
and UDP).

HELP!
 
R

Roady [MVP]

Aside that port 25 is used for sending mail, there is no direct relation of
your issue to Outlook (e.g; your issue would also occur with another mail
client). Your issue is apparently a general networking issue and there are
networking newsgroups for that in the Windows section.

Also, without specifying any details on your configuration and what exactly
you are doing it would be impossible to tell what is going on. It could be
from you not performing the Telnet commands correctly all the way to that
specific server not allowing port 25 for you anymore (Comcast for example is
gradually switching to port 587).
 
S

Shmoo

Thanks, Roady
I actually asked, in the 'Which Forum should I use" forum, and was sent here.
You are correct, it's not Outlook, also Thunderbird. I am telnetting
correctly:

C:\Users\Shmoo>telnet mail.netvision.net.il 25
Connecting To mail.netvision.net.il...Could not open connection to the host,
on
port 25: Connect failed

I also ran:

C:\Users\Shmoo>netstat -an -p tcp

Active Connections

Proto Local Address Foreign Address State
TCP 0.0.0.0:135 0.0.0.0:0 LISTENING
TCP 0.0.0.0:912 0.0.0.0:0 LISTENING
TCP 0.0.0.0:3389 0.0.0.0:0 LISTENING
TCP 0.0.0.0:49152 0.0.0.0:0 LISTENING

And you see, port 25 is not there.
My ISP was the one who told me to telnet 25, so they definitely are using
it. The rep said I should do something with netsh that would reset my
computer - but that there's a small chance it could format the computer, and
do I consent. I do not! There must be something simple here.
By config, what do you mean? I'm using Vista home premium :( on a laptop.
What else matters here?
I receive email and can surf.
Thanks much
 
N

N. Miller

After more than a year, I suddenly can't send emails. Telneting doesn't work,
and it's not in the list of listening ports.

Port 25 would only be in the list of listening ports if you were running a
mail server. Otherwise, nothing should be listening on port 25.
This started after I adjusted my wireless router to allow a friend on ...

If you are sharing your Comcast connection with a friend, and you have
access to a Comcast mail server without SMTP AUTH, your friend also had
access to that same server, and may have sent a few more email messages on
your connection that Comcast likes to see; leading to a port 25 blocking
config file on your modem. If you are not a Comcast customer, some other,
possibly comparable, scenario might apply.
... (where I had to change my Encryption setting), but it's related to my
computer, not the router, as it's still happening on a different network,
and others can send/telnet. Are there settings that could have changed?

I have no idea, because you have not said which ISP you have, or which email
services, if not your ISP's, you may be using.
 
S

Shmoo

Hi,
Okay, so you're saying the fact that it's not in the list is normal - I'm
not running a mail server.
I have 2 accounts set up one, in Outlook with Netvision.net.il, and another
in Thunderbird with Interal.co.il. My account settings are okay - I checked.
I'm not sure what you mean by email services, but as I said, I'm using ISPs.
Not sure what else I can add here.
Thanks though.
 
R

Roady [MVP]

Thanks for the additional info.

As you mention in your other thread that you are also using an other mail
account hosted by another ISP; does telnetting to their servers work?

The local connections are meaningless in this case for netstat as they are a
reflection of your open connections and not the one from the server.
Nevertheless, it is a short list if that is all what is being reported.

You can do a repair on your network adapter by opening the Network and
Sharing Center in Vista. You'll find Diagnose and Repair in the left Task
Pane.

To forcefully do a repair on the adapter click "Manage network connections"
in that same pane-> right click on your network adapter-> choose Diagnose
and follow on-screen instructions.
 
S

Shmoo

I must say, I take heart that someone is willing to help - thanx a million.
It's amazing how bad a feeling it is when this thing we've come to depend on
stops working!

Now, yes the list is partial, and N.Miller pointed out that port 25 wouldn't
be on that list anyway. Telnetting to ANYWHERE on 25 doesn't work. Is there a
site I can try it on that will diagnose the problem? I tried a couple, that
just reported what I already know - 25 is not responding.
The fix you mention doesn't help. Maybe when I get home I'll try the regular
LAN, although I'm not convinced it's a connection issue, rather a config
thing that got changed somehow.
 
R

Roady [MVP]

It's hard to determine a fix without knowing what exactly is wrong here and
what happened to make it that way ;-)

Are there any other firewalls perhaps still present on the system? It could
even be an infection on the computer itself which is blocking port 25 to be
used for anything else. Running a (up-to-date) virus scanner and a spyware
scanner might reveal this.

How does it behave when you start Windows in Safe Mode with Networking
Support?

Switching to a regular LAN connection is a good troubleshooting step to find
out if there is a (configuration) issue which is limited to the current
(wireless?) connection.
 
V

VanguardLH

Shmoo said:
After more than a year, I suddenly can't send emails. Telneting doesn't work,
and it's not in the list of listening ports. This started after I adjusted my
wireless router to allow a friend on (where Ihad to change my Encryption
setting), but it's related to my computer, not the router, as it's still
happening on a different network, and others can send/telnet. Are there
settings that could have changed? I tried turning off the MS Firewall,
uninstalling AVG, adding an exception to the firewall for port 25 (both tcp
and UDP).

HELP!

Some ISPs and other e-mail providers have discontinued using port 25.
This port should only be used for interconnections between SMTP mail
servers according to RFC 2476 ratified back in 1998
(http://www.rfc-editor.org/rfc/rfc2476.txt) but not implemented until
the last few years; however, all e-mail clients are still historically
hard-wired to use port 25 for non-SSL SMTP connects and port 995 for SSL
SMTP connects. Many times an e-mail provider might switch to a
different port and not notify their customers. Port 587 is the
submission port for clients to their SMTP mail host, per the RFC.

I don't read Hebrew so I cannot go look on their web site to see what
they claim are the proper ports to use when connecting to their SMTP
mail host.
 
N

N. Miller

This port should only be used for interconnections between SMTP mail
servers according to RFC 2476 ratified back in 1998 ...

FYI, RFC 2476 is now obsolete, replaced by RFC 4409; ratified April, 2006.

And RFC 2821 is now obsolete, replaced by RFC 5321; ratified October, 2008.

RFC 5321 specifically refers to RFC 4409, and specifically states that port
587 is the preferred message submission port.
 
N

N. Miller

Okay, so you're saying the fact that it's not in the list is normal - I'm
not running a mail server.
Yes.

I have 2 accounts set up one, in Outlook with Netvision.net.il, and another
in Thunderbird with Interal.co.il. My account settings are okay - I checked.
I'm not sure what you mean by email services, but as I said, I'm using ISPs.
Not sure what else I can add here.

All that I know is that U.S. ISPs have moved toward blocking port 25 access,
and using message submission ports. RFC 4409 outlines the message submission
port defined as "preferred" by RFC 5321. In the U.S. Comcast offer both port
587, and port 465 w/SSL for SMTP message submission, and AT&T also. That
covers the two largest U.S. HSI providers; about 28.4 million users, total.
You might want to check with your ISP and see if they are moving in the same
direction.
 
V

VanguardLH

N. Miller said:
FYI, RFC 2476 is now obsolete, replaced by RFC 4409; ratified April, 2006.

And RFC 2821 is now obsolete, replaced by RFC 5321; ratified October, 2008.

RFC 5321 specifically refers to RFC 4409, and specifically states that port
587 is the preferred message submission port.

My point is that no e-mail client currently defaults to port 587 for
SMTP connects whether non-SSL or SSL enabled. They all still default to
port 25 for non-SSL connects and port 995 for SSL connects. So the user
should see what their e-mail provider states is the correct port since
the defaults in the e-mail client may not be valid for that e-mail
provider (or the e-mail provider has changed to port 587 where they used
to use port 25). Also, many such e-mail providers that have or are
switching to the submission port of 587 are often out of sync in their
web help pages, and sometimes even their first-level tech reps haven't
been notified or are also relying on the same outdated web help pages.
So just try port 587 to see if the connection then works okay.

RFC 2476 was indeed obsoleted by RFC 4409. That doesn't obviate the
information in RFC 2476 regarding the submission port of 587 to be used
by endpoint clients to the SMTP mail host. Back in 1998 for RFC 2476
was when port 587 was suggested for endpoint submission by clients, not
in the later RFC 4409 which simply carried along the same suggestion.
 
S

Shmoo

This is a temporary update.
I took mt comp home and tried some things. I first configged a different
comp with the email account and sent mail - no prob.
I then tried with this comp, sending a mail to the 3 accounts I use. one
went through (this account actually just forwards my mail to one of the other
2), but the other 2 didn't go through - 551 - Relay denied. Telnetting
worked! I need to do this again today, being a little more scientific in my
methods, and I'll come back with the resolution, which might help someone
else someday. I will also try your suggestions at home.
Thanks a bunch
 
S

Shmoo

Okay, this is a final update, and a new question as a result.
I did as Roady suggested. Vista has 2 firewall options - the regular one and
one with
Advanced Security, which has three firewalls - Public, Private and Domain. I
turned all off, and also uninstalled AVG - not taking any chances here. At
any rate, it worked.

Now for the question. As I mentioned, I have two email accounts - one from
Netvision, my ISP, and another from work. The helpdesk for the work account
said I must have the out-going SMTP server be the ISP's server - not theirs.
I have had Outlook set up for a year now exclusively for the work account and
Thunderbird for the home account, with Outlook's SMTP server being the work
accounts' server with no probs. Is this correct - when at home I need to have
it pointing to Netvision, and at work to Atcom, and If I'll go somewhere
else, to whatever they are using there? Are there any rules for this
parameter?

Again, thanks for the encouragement.
 
N

N. Miller

My point is that no e-mail client currently defaults to port 587 for
SMTP connects whether non-SSL or SSL enabled.

Yet you referred to obsolete documents to make your point. *My point* was,
simply, that there are newer documents to support your point.
 
N

N. Miller

Okay, this is a final update, and a new question as a result.
I did as Roady suggested. Vista has 2 firewall options - the regular one and
one with
Advanced Security, which has three firewalls - Public, Private and Domain. I
turned all off, and also uninstalled AVG - not taking any chances here. At
any rate, it worked.

Now for the question. As I mentioned, I have two email accounts - one from
Netvision, my ISP, and another from work. The helpdesk for the work account
said I must have the out-going SMTP server be the ISP's server - not theirs.
I have had Outlook set up for a year now exclusively for the work account and
Thunderbird for the home account, with Outlook's SMTP server being the work
accounts' server with no probs. Is this correct - when at home I need to have
it pointing to Netvision, and at work to Atcom, and If I'll go somewhere
else, to whatever they are using there? Are there any rules for this
parameter?

Again, thanks for the encouragement.

To send email using your work email address, I'd find a generic email
service with SMTP message submission access from anyplace. In my case, my
ISP has SMTP message submission service accessible from any Internet
connection, using either port 587, or port 465 w/SSL, so that would work for
me. Not knowing if you could access the Netvision SMTP message submission
server "off-network", that might not work for you. You would then be faced
with learning the access rules for each network you affiliated with; a royal
PITA. A free Gmail account allows access via their SMTP message submission
server from any Internet connection, once you verify that your work email
address is an authorized "sender" for the account; at the expense of Gmail
scanning your work messages.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top