Cannot Send an Email to Comcast Email Account

Hi:

I have a Windows 2003 Small Business Server SP2. I'm using Covad as my ISP.
For some reason I cannot send an email to one of my client using a
comcast.net account, I get a Delivery to the following recipients has been
delayed error. Reverse DNS and PTR Records are all set but I'm running out of
Ideas on what to do, please help.
I can send email to the rest of the world without problem.


Thank You

On Thu, 28 Feb 2008 13:42:02 -0800
Kobe Cunanan <KobeCunanan@discussions.microsoft.com> wrote:

>Hi:
>
>I have a Windows 2003 Small Business Server SP2. I'm using Covad as my
>ISP. For some reason I cannot send an email to one of my client using
>a comcast.net account, I get a Delivery to the following recipients
>has been delayed error. Reverse DNS and PTR Records are all set but
>I'm running out of Ideas on what to do, please help.
>I can send email to the rest of the world without problem.
>
>
>Thank You
>

Is your MX record valid?
Is his address valid and verified? Can you send hi from a private
account and verify he receives the mail?

--
Holz
:-)

Hi:

Yes I verify the MX record is valid and yes I tried sending him an email
from my private account and he got it.

"Holz" wrote:

>
>
> On Thu, 28 Feb 2008 13:42:02 -0800
> Kobe Cunanan <KobeCunanan@discussions.microsoft.com> wrote:
>
> >Hi:
> >
> >I have a Windows 2003 Small Business Server SP2. I'm using Covad as my
> >ISP. For some reason I cannot send an email to one of my client using
> >a comcast.net account, I get a Delivery to the following recipients
> >has been delayed error. Reverse DNS and PTR Records are all set but
> >I'm running out of Ideas on what to do, please help.
> >I can send email to the rest of the world without problem.
> >
> >
> >Thank You
> >
>
> Is your MX record valid?
> Is his address valid and verified? Can you send hi from a private
> account and verify he receives the mail?
>
> --
> Holz
> :-)
>
>

On Thu, 28 Feb 2008 14:46:03 -0800
Kobe Cunanan <KobeCunanan@discussions.microsoft.com> wrote:

>Hi:
>
>Yes I verify the MX record is valid and yes I tried sending him an
>email from my private account and he got it.

It means that somewhere on his end you are somehow blocked. Either by
him or Comcast.

--
Holz
:-)

On Thu, 28 Feb 2008 13:42:02 -0800, Kobe Cunanan
<KobeCunanan@discussions.microsoft.com> wrote:

>Hi:
>
>I have a Windows 2003 Small Business Server SP2. I'm using Covad as my ISP.
>For some reason I cannot send an email to one of my client using a
>comcast.net account, I get a Delivery to the following recipients has been
>delayed error. Reverse DNS and PTR Records are all set but I'm running out of
>Ideas on what to do, please help.
>I can send email to the rest of the world without problem.
>
>
>Thank You
I have seen servers blocked if the name of the server in the default
smtp virtual server is not the same as the mx record.

Jim Behning SBS MVP wrote:
> On Thu, 28 Feb 2008 13:42:02 -0800, Kobe Cunanan
> <KobeCunanan@discussions.microsoft.com> wrote:
>
>> Hi:
>>
>> I have a Windows 2003 Small Business Server SP2. I'm using Covad as my ISP.
>> For some reason I cannot send an email to one of my client using a
>> comcast.net account, I get a Delivery to the following recipients has been
>> delayed error. Reverse DNS and PTR Records are all set but I'm running out of
>> Ideas on what to do, please help.
>> I can send email to the rest of the world without problem.
>>
>>
>> Thank You
> I have seen servers blocked if the name of the server in the default
> smtp virtual server is not the same as the mx record.

I've seen rumours that Comcast does exactly that. Check the FQDN of the
SMTP Virtual Server, and adjust it to match the MX record. Sane mail
servers just look for a valid hostname or domain name here, as there
isn't really any reason why outgoing mail should originate from the same
machine or even the same network as incoming mail goes to. Not all
relaying is carried out by spammers, and the relay facility wouldn't
exist in SMTP if it didn't have legitimate purposes. Having the FQDN
entry in Exchange is a cheat anyway, the HELO is 'supposed' to be the
actual hostname of the outgoing mail server, which it can never be with
a 'best-practices' SBS.

If this matching requirement becomes common (AOL doesn't do it, and
they're pretty fussy) then all that will happen is that spammers will
start looking up domain MX records. They already have to forge the HELO,
copying the MX to it is trivial to do. Many orders of magnitude easier
than creating a valid PTR record for a dynamic IP address.

Jim, what does this mean irl? That you need a seperate virtual server for
each possible domain name (if you use more then one) in use?
Or do I completely got It backwards, upwards or not at all?

--
Henrik Arenblad, MCP SBS,







"Jim Behning SBS MVP" <jimbehning@doesthisblockpork.mindspring.com> wrote in
message news:j8mes35djtkj66ch886ge52ehpa2f9o7da@4ax.com...
> On Thu, 28 Feb 2008 13:42:02 -0800, Kobe Cunanan
> <KobeCunanan@discussions.microsoft.com> wrote:
>
>>Hi:
>>
>>I have a Windows 2003 Small Business Server SP2. I'm using Covad as my
>>ISP.
>>For some reason I cannot send an email to one of my client using a
>>comcast.net account, I get a Delivery to the following recipients has been
>>delayed error. Reverse DNS and PTR Records are all set but I'm running out
>>of
>>Ideas on what to do, please help.
>>I can send email to the rest of the world without problem.
>>
>>
>>Thank You
> I have seen servers blocked if the name of the server in the default
> smtp virtual server is not the same as the mx record.

No, it means that the name of the depths of the Exchange default
virtual server had to match my mx record. Just the default virtual
server that every SBS has. No new .

Exchange System Manager\Administrative Groups\first administrative
group\Servers\servername\Protocols\SMTP\Default SMTP Virtual Server
Properties\Delivery\Advanced\Fully-qualified domain name is the only
thing I have had to do. And actually only at one or two accounts. It
may relate to the quality of the isp. Some ISPs may have their ips
registered in a way that annoys some other domains. Those annoying
ISPs do not even understand what they are doing wrong. The bigger ISPs
respond to send problems quickly but those smaller problem ISPs do not
get the issue even when I send them the article that explains it. I do
not have the article in front of me but it boils down to this. You buy
a static ip. The ISP does not "register" the ip as a static ip to the
rest of the real world. Some mail servers see that ip as a coming from
a block of dynamic ips so they block your server. Email servers only
send from static ips, right? http://itvibe.com/news/3858/ I think we
had asked for a rdns at my one account that was having Comcast issues.
I know that acount that had issues with Comcast does have a rdns entry
right now that points to their mail server.

Now the confusing thing is in the real world I can do a mx lookup for
a big corporation and they may list 3 or 4 receiving email servers but
they send email with 4 different email servers that are not in the
list.

On Mon, 3 Mar 2008 12:42:06 +0100, "Henrik" <hear01@hotmail.com>
wrote:

>Jim, what does this mean irl? That you need a seperate virtual server for
>each possible domain name (if you use more then one) in use?
>Or do I completely got It backwards, upwards or not at all?
>
>--
>Henrik Arenblad, MCP SBS,
>
>
>
>
>
>
>
>"Jim Behning SBS MVP" <jimbehning@doesthisblockpork.mindspring.com> wrote in
>message news:j8mes35djtkj66ch886ge52ehpa2f9o7da@4ax.com...
>> On Thu, 28 Feb 2008 13:42:02 -0800, Kobe Cunanan
>> <KobeCunanan@discussions.microsoft.com> wrote:
>>
>>>Hi:
>>>
>>>I have a Windows 2003 Small Business Server SP2. I'm using Covad as my
>>>ISP.
>>>For some reason I cannot send an email to one of my client using a
>>>comcast.net account, I get a Delivery to the following recipients has been
>>>delayed error. Reverse DNS and PTR Records are all set but I'm running out
>>>of
>>>Ideas on what to do, please help.
>>>I can send email to the rest of the world without problem.
>>>
>>>
>>>Thank You
>> I have seen servers blocked if the name of the server in the default
>> smtp virtual server is not the same as the mx record.
>

Thanks Jim, That explains enough for me.
I went In and had a look at my own SBS in the path you wrote before your
respons, what you just wrote was exprox. what I thought.
I couldn´t realy connect this when looking at the settings (my own Q about
several virtual servers - A dumb Q from my side).

Thanks again for the clarification

--
Henrik Arenblad, MCP SBS,







"Jim Behning SBS MVP" <jimbehning@doesthisblockpork.mindspring.com> wrote in
message news:ubuns3d032gsp6s4e8n2hp910l92p7tkvu@4ax.com...
> No, it means that the name of the depths of the Exchange default
> virtual server had to match my mx record. Just the default virtual
> server that every SBS has. No new .
>
> Exchange System Manager\Administrative Groups\first administrative
> group\Servers\servername\Protocols\SMTP\Default SMTP Virtual Server
> Properties\Delivery\Advanced\Fully-qualified domain name is the only
> thing I have had to do. And actually only at one or two accounts. It
> may relate to the quality of the isp. Some ISPs may have their ips
> registered in a way that annoys some other domains. Those annoying
> ISPs do not even understand what they are doing wrong. The bigger ISPs
> respond to send problems quickly but those smaller problem ISPs do not
> get the issue even when I send them the article that explains it. I do
> not have the article in front of me but it boils down to this. You buy
> a static ip. The ISP does not "register" the ip as a static ip to the
> rest of the real world. Some mail servers see that ip as a coming from
> a block of dynamic ips so they block your server. Email servers only
> send from static ips, right? http://itvibe.com/news/3858/ I think we
> had asked for a rdns at my one account that was having Comcast issues.
> I know that acount that had issues with Comcast does have a rdns entry
> right now that points to their mail server.
>
> Now the confusing thing is in the real world I can do a mx lookup for
> a big corporation and they may list 3 or 4 receiving email servers but
> they send email with 4 different email servers that are not in the
> list.
>
> On Mon, 3 Mar 2008 12:42:06 +0100, "Henrik" <hear01@hotmail.com>
> wrote:
>
>>Jim, what does this mean irl? That you need a seperate virtual server for
>>each possible domain name (if you use more then one) in use?
>>Or do I completely got It backwards, upwards or not at all?
>>
>>--
>>Henrik Arenblad, MCP SBS,
>>
>>
>>
>>
>>
>>
>>
>>"Jim Behning SBS MVP" <jimbehning@doesthisblockpork.mindspring.com> wrote
>>in
>>message news:j8mes35djtkj66ch886ge52ehpa2f9o7da@4ax.com...
>>> On Thu, 28 Feb 2008 13:42:02 -0800, Kobe Cunanan
>>> <KobeCunanan@discussions.microsoft.com> wrote:
>>>
>>>>Hi:
>>>>
>>>>I have a Windows 2003 Small Business Server SP2. I'm using Covad as my
>>>>ISP.
>>>>For some reason I cannot send an email to one of my client using a
>>>>comcast.net account, I get a Delivery to the following recipients has
>>>>been
>>>>delayed error. Reverse DNS and PTR Records are all set but I'm running
>>>>out
>>>>of
>>>>Ideas on what to do, please help.
>>>>I can send email to the rest of the world without problem.
>>>>
>>>>
>>>>Thank You
>>> I have seen servers blocked if the name of the server in the default
>>> smtp virtual server is not the same as the mx record.
>>

GAAHH - Spelling errors ... here Is what I should have written ...

I went In and had a look at my own SBS in the path you wrote before your
respons, what you just wrote was approximatly / almost what I thought.

--
Henrik Arenblad, MCP SBS,


"Henrik" <hear01@remove-this-hotmail.com> wrote in message
news:eQe1AVTfIHA.4144@TK2MSFTNGP05.phx.gbl...
> Thanks Jim, That explains enough for me.
> I went In and had a look at my own SBS in the path you wrote before your
> respons, what you just wrote was exprox. what I thought.
> I couldn´t realy connect this when looking at the settings (my own Q about
> several virtual servers - A dumb Q from my side).

(snipped)