I have a problem which I cannot explain : in my office, I have an XP SP2
machine running Norton SBS 10.1 which acts as the mail server. I have two
broadband connections from two different ISPs. Through one, there is
absolutey no problem When I shift to the other, Internet access if perfect,
accessing POP3 accounts, but accessaing my SMTP server : waits for ever. Or
sort of. Suddenly, after say 15 minutes, the mails go. And then again, server
timeout.
When I get back to the first ISP, absolutely no problem. I checked with my
Web Site hoster, and they replied that theuy have not blocked SMTP access to
the address space that the second ISP uses.
BTW, on the first ISP, I have a static IP, while on the second I get a
dynamic IP. The proxy server is Freeproxy, but the problem remains even if
the proxy is bypassed by the email client on the mail server.
Any ideas?

Mohan

--
Message posted via http://www.windowskb.com

(cross-post added to XP Networking)
"bnmohan via WindowsKB.com" u35859@uwe wrote in message
news:75a59cfc37fec@uwe...
I have a problem which I cannot explain : in my office, I have an XP SP2
machine running Norton SBS 10.1 which acts as the mail server. I have two
broadband connections from two different ISPs. Through one, there is
absolutey no problem When I shift to the other, Internet access if perfect,
accessing POP3 accounts, but accessaing my SMTP server : waits for ever. Or
sort of. Suddenly, after say 15 minutes, the mails go. And then again, server
timeout.
When I get back to the first ISP, absolutely no problem. I checked with my
Web Site hoster, and they replied that theuy have not blocked SMTP access to
the address space that the second ISP uses.


It's not clear what your "Web Site hoster" has to do with your problem SMTP
service. Is that one of your ISPs? Which one?


BTW, on the first ISP, I have a static IP, while on the second I get a
dynamic IP. The proxy server is Freeproxy, but the problem remains even if
the proxy is bypassed by the email client on the mail server.
Any ideas?


Sounds as if the dynamic IP address is not being used?
Have you tried forcing it to be used? I'm not sure how to do that.
Perhaps just powering off the network adapter with the static address?


ipconfig /all and netstat -r (commands for cmd window)
might provide more clues. Also is a router involved?
Otherwise probably the clearest clues about what is happening
would be found in a packet trace or other network diagnostic
which can show the IP addresses being used to transport the SMTP
request. E.g. if it is being done by the other ISP's IP address
it would be clear that it would appear as a request from an unknown
possibly unauthorized poster and hence perhaps be ignored.
If the second request (after the timeout) was sent using the ISP's IP address
then it would appear authorized and not be ignored. Etc.

A potential solution would be to use an authenticating SMTP protocol
(e.g. using a different port than 25, which does not require authentication.)


BTW solving multi-home issues like this would probably be best done
in a newsgroup which specializes in networking. Cross-posting for convenience.


Good luck

Robert Aldwinckle
---



Mohan

--
Message posted via http://www.windowskb.com

Hi! 24 July

Thanks a lot. And sorry about the typing errors.

I have two adaptors on the mail server : one connected to the local office
lan, the other to the broadband router.
When I connect to the static IP ISP, the static IP terminates on the adaptor,
the gateway being the router IP, and the router is in bridge mode. By
connecting I mean a lan cable between the router and the lan card.
When I connect to the triband dyanmic IP ISP (I remove the lan cable from
the earlier router and connect it to the second one), I change the ip address
of the adaptor to 192.168.1.xxx, with gateway 192.168.1.1 (on the triband
router).
By Website Hoster I mean the company who host my domain : If they have for
some reason blocked access to the SMTP port for addresses in the space 59.184.
xxx.xxx, then no mails ever would move. But some do : once in say 15 or 20
mins, or even more. But POP3 access is NO problem, nor is access to the
internet.
And I used both the connections without any problem earlier (some three four
weeks earlier: I used to alternate between the two)
I therefore think the problem lies with my ISP, but I am not able to prove
anything.

Mohan
Robert Aldwinckle wrote:
(cross-post added to XP Networking)
I have a problem which I cannot explain : in my office, I have an XP SP2
machine running Norton SBS 10.1 which acts as the mail server. I have two
[quoted text clipped - 6 lines]
Web Site hoster, and they replied that theuy have not blocked SMTP access to
the address space that the second ISP uses.

It's not clear what your "Web Site hoster" has to do with your problem SMTP
service. Is that one of your ISPs? Which one?

BTW, on the first ISP, I have a static IP, while on the second I get a
dynamic IP. The proxy server is Freeproxy, but the problem remains even if
the proxy is bypassed by the email client on the mail server.
Any ideas?

Sounds as if the dynamic IP address is not being used?
Have you tried forcing it to be used? I'm not sure how to do that.
Perhaps just powering off the network adapter with the static address?

ipconfig /all and netstat -r (commands for cmd window)
might provide more clues. Also is a router involved?
Otherwise probably the clearest clues about what is happening
would be found in a packet trace or other network diagnostic
which can show the IP addresses being used to transport the SMTP
request. E.g. if it is being done by the other ISP's IP address
it would be clear that it would appear as a request from an unknown
possibly unauthorized poster and hence perhaps be ignored.
If the second request (after the timeout) was sent using the ISP's IP address
then it would appear authorized and not be ignored. Etc.

A potential solution would be to use an authenticating SMTP protocol
(e.g. using a different port than 25, which does not require authentication.)

BTW solving multi-home issues like this would probably be best done
in a newsgroup which specializes in networking. Cross-posting for convenience.

Good luck

Robert Aldwinckle
---

Mohan

--
Message posted via WindowsKB.com
http://www.windowskb.com/Uwe/Forums....press/200707/1

"bnmohan via WindowsKB.com" wrote in message news:75a59cfc37fec@uwe...
I have a problem which I cannot explain : in my office, I have an XP
SP2
machine running Norton SBS 10.1 which acts as the mail server. I have
two
broadband connections from two different ISPs. Through one, there is
absolutey no problem When I shift to the other, Internet access if
perfect,
accessing POP3 accounts, but accessaing my SMTP server : waits for
ever. Or
sort of. Suddenly, after say 15 minutes, the mails go. And then again,
server
timeout.
When I get back to the first ISP, absolutely no problem. I checked
with my
Web Site hoster, and they replied that theuy have not blocked SMTP
access to
the address space that the second ISP uses.
BTW, on the first ISP, I have a static IP, while on the second I get a
dynamic IP. The proxy server is Freeproxy, but the problem remains
even if
the proxy is bypassed by the email client on the mail server.

Unless you have a business account whose TOS says that you can run
servers on your own hosts, don't expect your ISP to permit them. For
personal accounts, your ISP may require that you use their mail servers
(and may even further restrict that you cannot connect to off-domain
mail hosts). Sounds like they may have not simply blocked all access to
off-domain mail hosts, including yours, but instead have instituted an
anti-spam quota as to how often you can get at them.

Don't know what is Freeproxy (other than the indication that is it some
kind of proxy). If you are trying to route your mails through a public
relay then maybe your ISP is using DNS blocklists of known spam sources,
and that includes open proxies. Use something like DynDNS to provide an
IP name for your dynamically IP addressed host (actually that'll only
get you to the WAN side of your router *if* you router supports DynDNS,
or you'll have to run their client that runs on your mail host to report
its IP address in that intranetwork to DynDNS).

I think your second para was the problem/solution: my account with my ISPs is
used only to access the Internet, and I do not use their servers for Email.
My POP3 and SMTP servers are on my domain hosted elsewhere. I had therefore
not even created the free email account that they provide. It appears that
for traffic from non-registered EMAIL users, there is some sort of access
control on how often port 25 is sought to be accessed via their connection. I
created my free email account, and mail now goes through smoothly.
Now I have to watch that account.
I am not sure I get the logic and reasoning behind the setup at my ISP.
Wonder if someone could take me around.

Mohan

Vanguard wrote:
I have a problem which I cannot explain : in my office, I have an XP
SP2
[quoted text clipped - 17 lines]
even if
the proxy is bypassed by the email client on the mail server.

Unless you have a business account whose TOS says that you can run
servers on your own hosts, don't expect your ISP to permit them. For
personal accounts, your ISP may require that you use their mail servers
(and may even further restrict that you cannot connect to off-domain
mail hosts). Sounds like they may have not simply blocked all access to
off-domain mail hosts, including yours, but instead have instituted an
anti-spam quota as to how often you can get at them.

Don't know what is Freeproxy (other than the indication that is it some
kind of proxy). If you are trying to route your mails through a public
relay then maybe your ISP is using DNS blocklists of known spam sources,
and that includes open proxies. Use something like DynDNS to provide an
IP name for your dynamically IP addressed host (actually that'll only
get you to the WAN side of your router *if* you router supports DynDNS,
or you'll have to run their client that runs on your mail host to report
its IP address in that intranetwork to DynDNS).

--
Message posted via WindowsKB.com
http://www.windowskb.com/Uwe/Forums....press/200707/1

I mean the second part and not second para where you mentioned the acces
control to SMTP.

Mohan

bnmohan wrote:
I think your second para was the problem/solution: my account with my ISPs is
used only to access the Internet, and I do not use their servers for Email.
My POP3 and SMTP servers are on my domain hosted elsewhere. I had therefore
not even created the free email account that they provide. It appears that
for traffic from non-registered EMAIL users, there is some sort of access
control on how often port 25 is sought to be accessed via their connection. I
created my free email account, and mail now goes through smoothly.
Now I have to watch that account.
I am not sure I get the logic and reasoning behind the setup at my ISP.
Wonder if someone could take me around.

Mohan

I have a problem which I cannot explain : in my office, I have an XP
SP2
[quoted text clipped - 18 lines]
or you'll have to run their client that runs on your mail host to report
its IP address in that intranetwork to DynDNS).

--
Message posted via WindowsKB.com
http://www.windowskb.com/Uwe/Forums....press/200707/1

"bnmohan via WindowsKB.com" wrote in message news:75d5283163971@uwe...
I think your second para was the problem/solution: my account with my
ISPs is
used only to access the Internet, and I do not use their servers for
Email.
My POP3 and SMTP servers are on my domain hosted elsewhere. I had
therefore
not even created the free email account that they provide. It appears
that
for traffic from non-registered EMAIL users, there is some sort of
access
control on how often port 25 is sought to be accessed via their
connection. I
created my free email account, and mail now goes through smoothly.
Now I have to watch that account.
I am not sure I get the logic and reasoning behind the setup at my
ISP.
Wonder if someone could take me around.

You are connecting to your ISP. They want you using their mail server
to track any spam abuse that gets reported to them. They can use their
logs to determine from the headers of the reported spam which account
was connected using what IP address when the spam got sent through their
mail server. If it doesn't come through their mail server then they
could still use the log to check up on who was using the sending IP
address if their customer was running their own mail server. Doesn't
sound like you are running a mail server on your own host which is
connected to your ISP.

Besides requiring that you connect via port 25 to *their* mail server,
the other anti-spam restriction is blocking their customers from sending
e-mails through a mail server that is off their domain. That is, you
are trying to connect your e-mail client to a mail server that is not on
their domain. For many ISPs, they won't allow this inbound connection
from some other domain, so you can't get to their domain from your
domain (I.e., they block inbound connects to their mail servers that
come from somewhere other than their own customers on their domain).
For your ISP, they may preempt that restriction and not let you get
across their network to connect to some off-domain mail server. So you
have mail servers that allow connects only by customers on the same
domain as the mail server, and you have ISPs that won't let you cross
their domain to connect to some off-domain mail server. It's all to
enforce tracking of who is sending what to nail the spam sources.

For those domains that do not permit off-domain connects *to* their mail
server, sometimes they will provide an alternate setup to connect to
them. For example, off-domain connections to my Comcast mail server
requires that I enable SSL connects and use port 995 instead of 110 for
POP3 and use port 465 instead of 25 for SMTP. There might be another
option required, too, like SPA. So the e-mail config I use at home
while on their network is not the same config when I am travelling and
have to come from off-domain to connect to their mail servers.

For those domains that do not permit you to cross over their network to
connect to some off-domain mail servers, they are blocking traffic from
entering their domain and then leaving it that uses port 25 (although
protocol analyzers could also be used so as not to simply rely on the
port number). To get around this, some mail servers let you use
non-standard ports to connect to their mail servers. That way, the
network you are crossing won't block your on port 25 because you are
using some other port number. SSL connects on 995 for POP3 and 465 for
SMTP are often used for this.

Since you are crossing your ISP's network to connect to an off-domain
mail server provided by e-mail provider that you choose to use, find out
what port configs they permit for off-domain connections (i.e., you are
coming into their domain from somewhere off their domain). Maybe they
permit SSL connects using non-standard port numbers, or maybe the use
the standard ports and rely on your login credentials to prove you are
their customer and are authenticated to use their resources. If you
can't connect using the standard ports to their mail server because your
ISP is blocking traffic over port 25, you'll have to use non-standard
ports.

Thanks a lot!

I created the email ID that my Broadband provider provides. Now mail goes
(via my SMTP on my domain hosted at Jumpline). I havent even configured that
email ID anywhere. So maybe the creation of the email ID opens up some port
on some router/switch on their system in the process of configuring that new
ID.

Thanks anyway. I am finding this forum most enjoyable, and informative!

Mohan

Vanguard wrote:
I think your second para was the problem/solution: my account with my
ISPs is
[quoted text clipped - 13 lines]
ISP.
Wonder if someone could take me around.

You are connecting to your ISP. They want you using their mail server
to track any spam abuse that gets reported to them. They can use their
logs to determine from the headers of the reported spam which account
was connected using what IP address when the spam got sent through their
mail server. If it doesn't come through their mail server then they
could still use the log to check up on who was using the sending IP
address if their customer was running their own mail server. Doesn't
sound like you are running a mail server on your own host which is
connected to your ISP.

Besides requiring that you connect via port 25 to *their* mail server,
the other anti-spam restriction is blocking their customers from sending
e-mails through a mail server that is off their domain. That is, you
are trying to connect your e-mail client to a mail server that is not on
their domain. For many ISPs, they won't allow this inbound connection
from some other domain, so you can't get to their domain from your
domain (I.e., they block inbound connects to their mail servers that
come from somewhere other than their own customers on their domain).
For your ISP, they may preempt that restriction and not let you get
across their network to connect to some off-domain mail server. So you
have mail servers that allow connects only by customers on the same
domain as the mail server, and you have ISPs that won't let you cross
their domain to connect to some off-domain mail server. It's all to
enforce tracking of who is sending what to nail the spam sources.

For those domains that do not permit off-domain connects *to* their mail
server, sometimes they will provide an alternate setup to connect to
them. For example, off-domain connections to my Comcast mail server
requires that I enable SSL connects and use port 995 instead of 110 for
POP3 and use port 465 instead of 25 for SMTP. There might be another
option required, too, like SPA. So the e-mail config I use at home
while on their network is not the same config when I am travelling and
have to come from off-domain to connect to their mail servers.

For those domains that do not permit you to cross over their network to
connect to some off-domain mail servers, they are blocking traffic from
entering their domain and then leaving it that uses port 25 (although
protocol analyzers could also be used so as not to simply rely on the
port number). To get around this, some mail servers let you use
non-standard ports to connect to their mail servers. That way, the
network you are crossing won't block your on port 25 because you are
using some other port number. SSL connects on 995 for POP3 and 465 for
SMTP are often used for this.

Since you are crossing your ISP's network to connect to an off-domain
mail server provided by e-mail provider that you choose to use, find out
what port configs they permit for off-domain connections (i.e., you are
coming into their domain from somewhere off their domain). Maybe they
permit SSL connects using non-standard port numbers, or maybe the use
the standard ports and rely on your login credentials to prove you are
their customer and are authenticated to use their resources. If you
can't connect using the standard ports to their mail server because your
ISP is blocking traffic over port 25, you'll have to use non-standard
ports.

--
Message posted via http://www.windowskb.com