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From: Jeff on 21 May 2010 12:25
Hello all,

Several months ago my company could not send emails to Comcast. I found out
we were blocked. I filled out there request form to get unblocked and a
couple of hours later they opened the pipe.

Now, about once a month we keep getting blocked. Only from Comcast. I then
fill out their form and they unblock us.

I am running Exchange 2003 and using Symantec's Mail Security for Microsoft
Exchange. This seems to do a pretty good job blocking incoming spam.

Any idea why they continue to block us? What can I look at the help resolve
this??

Thanks,
Jeff
From: John Oliver, Jr. [MVP] on 22 May 2010 08:18
Do you have an SPF Record? Do you have Reverse DNS Lookup Record? Verify
this and if you are Blacklisted for any reason at www.dnsstuff.com. Does
Comcast give a reason as why they are blocking you?

--
John Oliver, Jr
MCSE, MCT, CCNA
Exchange MVP 2010
Microsoft Certified Partner


"Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
news:6EE5C287-B030-4704-AD0C-A314F9A640AC(a)microsoft.com...
> Hello all,
>
> Several months ago my company could not send emails to Comcast. I found
> out
> we were blocked. I filled out there request form to get unblocked and a
> couple of hours later they opened the pipe.
>
> Now, about once a month we keep getting blocked. Only from Comcast. I then
> fill out their form and they unblock us.
>
> I am running Exchange 2003 and using Symantec's Mail Security for
> Microsoft
> Exchange. This seems to do a pretty good job blocking incoming spam.
>
> Any idea why they continue to block us? What can I look at the help
> resolve
> this??
>
> Thanks,
> Jeff

From: Jeff on 24 May 2010 14:07
Yes,

I have an SPF record and reverse DNS Lookup that is configured properly.
I've done a lot of those online "tests" and it always comes back ok.

They don't give a reason. Once you fill out their form to get unblocked they
send an auto generated email saying:

"Our filters have determined that email from the IP you submitted was
blocked because it sent email to the Comcast domain with patterns
characteristics of spam. Mail servers are typically shared by many users so
it may be the case that another party using your mail server has sent spam,
even if you have not....."

Any other ideas to see if our sever is actually sending spam without me
knowing?


"John Oliver, Jr. [MVP]" wrote:

> Do you have an SPF Record? Do you have Reverse DNS Lookup Record? Verify
> this and if you are Blacklisted for any reason at www.dnsstuff.com. Does
> Comcast give a reason as why they are blocking you?
>
> --
> John Oliver, Jr
> MCSE, MCT, CCNA
> Exchange MVP 2010
> Microsoft Certified Partner
>
>
> "Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
> news:6EE5C287-B030-4704-AD0C-A314F9A640AC(a)microsoft.com...
> > Hello all,
> >
> > Several months ago my company could not send emails to Comcast. I found
> > out
> > we were blocked. I filled out there request form to get unblocked and a
> > couple of hours later they opened the pipe.
> >
> > Now, about once a month we keep getting blocked. Only from Comcast. I then
> > fill out their form and they unblock us.
> >
> > I am running Exchange 2003 and using Symantec's Mail Security for
> > Microsoft
> > Exchange. This seems to do a pretty good job blocking incoming spam.
> >
> > Any idea why they continue to block us? What can I look at the help
> > resolve
> > this??
> >
> > Thanks,
> > Jeff
>
From: John Oliver, Jr. [MVP] on 24 May 2010 14:18
Jeff,

Can you please give some info on your ISP setup? Are you using them as a
Smarthost or anyone else for that matter? Do you have a Business Static IP
account from your ISP or is it Residential? I would suggest the Smarthost
option as this point as your ISP mail server IP range are mostly whitelisted
and would allow the mail to go through. Please clarify. Thanks.

--
John Oliver, Jr
MCSE, MCT, CCNA
Exchange MVP 2010
Microsoft Certified Partner


"Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
news:9F47B39F-4C81-4F27-BE7D-8E3239418662(a)microsoft.com...
> Yes,
>
> I have an SPF record and reverse DNS Lookup that is configured properly.
> I've done a lot of those online "tests" and it always comes back ok.
>
> They don't give a reason. Once you fill out their form to get unblocked
> they
> send an auto generated email saying:
>
> "Our filters have determined that email from the IP you submitted was
> blocked because it sent email to the Comcast domain with patterns
> characteristics of spam. Mail servers are typically shared by many users
> so
> it may be the case that another party using your mail server has sent
> spam,
> even if you have not....."
>
> Any other ideas to see if our sever is actually sending spam without me
> knowing?
>
>
> "John Oliver, Jr. [MVP]" wrote:
>
>> Do you have an SPF Record? Do you have Reverse DNS Lookup Record?
>> Verify
>> this and if you are Blacklisted for any reason at www.dnsstuff.com. Does
>> Comcast give a reason as why they are blocking you?
>>
>> --
>> John Oliver, Jr
>> MCSE, MCT, CCNA
>> Exchange MVP 2010
>> Microsoft Certified Partner
>>
>>
>> "Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
>> news:6EE5C287-B030-4704-AD0C-A314F9A640AC(a)microsoft.com...
>> > Hello all,
>> >
>> > Several months ago my company could not send emails to Comcast. I found
>> > out
>> > we were blocked. I filled out there request form to get unblocked and a
>> > couple of hours later they opened the pipe.
>> >
>> > Now, about once a month we keep getting blocked. Only from Comcast. I
>> > then
>> > fill out their form and they unblock us.
>> >
>> > I am running Exchange 2003 and using Symantec's Mail Security for
>> > Microsoft
>> > Exchange. This seems to do a pretty good job blocking incoming spam.
>> >
>> > Any idea why they continue to block us? What can I look at the help
>> > resolve
>> > this??
>> >
>> > Thanks,
>> > Jeff
>>
From: Jeff on 24 May 2010 16:30
Our Exchange server has a static IP that was given to us 7 years ago by our
ISP.
Our ISP manages our DNS (which I can modify any time)
This is NOT Residential internet service.

We are not doing a relay with our ISP - Everything is static.

Comcast is the only problem we're having.

One thing that may be an issue, which I would like your opinion - Our firm's
signature file in Outlook consists of 3 attachments (graphics files) We are
also sending email as HTML and not plain text.

Thanks for your help so far.
Jeff


"John Oliver, Jr. [MVP]" wrote:

> Jeff,
>
> Can you please give some info on your ISP setup? Are you using them as a
> Smarthost or anyone else for that matter? Do you have a Business Static IP
> account from your ISP or is it Residential? I would suggest the Smarthost
> option as this point as your ISP mail server IP range are mostly whitelisted
> and would allow the mail to go through. Please clarify. Thanks.
>
> --
> John Oliver, Jr
> MCSE, MCT, CCNA
> Exchange MVP 2010
> Microsoft Certified Partner
>
>
> "Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
> news:9F47B39F-4C81-4F27-BE7D-8E3239418662(a)microsoft.com...
> > Yes,
> >
> > I have an SPF record and reverse DNS Lookup that is configured properly.
> > I've done a lot of those online "tests" and it always comes back ok.
> >
> > They don't give a reason. Once you fill out their form to get unblocked
> > they
> > send an auto generated email saying:
> >
> > "Our filters have determined that email from the IP you submitted was
> > blocked because it sent email to the Comcast domain with patterns
> > characteristics of spam. Mail servers are typically shared by many users
> > so
> > it may be the case that another party using your mail server has sent
> > spam,
> > even if you have not....."
> >
> > Any other ideas to see if our sever is actually sending spam without me
> > knowing?
> >
> >
> > "John Oliver, Jr. [MVP]" wrote:
> >
> >> Do you have an SPF Record? Do you have Reverse DNS Lookup Record?
> >> Verify
> >> this and if you are Blacklisted for any reason at www.dnsstuff.com. Does
> >> Comcast give a reason as why they are blocking you?
> >>
> >> --
> >> John Oliver, Jr
> >> MCSE, MCT, CCNA
> >> Exchange MVP 2010
> >> Microsoft Certified Partner
> >>
> >>
> >> "Jeff" <Jeff(a)discussions.microsoft.com> wrote in message
> >> news:6EE5C287-B030-4704-AD0C-A314F9A640AC(a)microsoft.com...
> >> > Hello all,
> >> >
> >> > Several months ago my company could not send emails to Comcast. I found
> >> > out
> >> > we were blocked. I filled out there request form to get unblocked and a
> >> > couple of hours later they opened the pipe.
> >> >
> >> > Now, about once a month we keep getting blocked. Only from Comcast. I
> >> > then
> >> > fill out their form and they unblock us.
> >> >
> >> > I am running Exchange 2003 and using Symantec's Mail Security for
> >> > Microsoft
> >> > Exchange. This seems to do a pretty good job blocking incoming spam.
> >> >
> >> > Any idea why they continue to block us? What can I look at the help
> >> > resolve
> >> > this??
> >> >
> >> > Thanks,
> >> > Jeff
> >>
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