Sending email error using Outlook on Comcast

[mark]

One of employees has Comcast at home for his hi speed cable / internet
and has a wireless router. He does not use the Comcast email account,
but uses our "Covad" provided email. He can get on line, get emails
on outlook but cannot send. Comcast on the phone said they could not
help because I was using Outlook. It does not appear to be a Covad
issue, beacuse it works fine everywhere else. I tried other laptos as
well in his house and we cannot send either.

Not sure what to do.

 

[K. Orland]

What is the error message when the user tries to send? Please include the
error message and/or number.

 

[N. Miller]

One of employees has Comcast at home for his hi speed cable / internet
and has a wireless router. He does not use the Comcast email account,
but uses our "Covad" provided email. He can get on line, get emails
on outlook but cannot send. Comcast on the phone said they could not
help because I was using Outlook. It does not appear to be a Covad
issue, beacuse it works fine everywhere else. I tried other laptos as
well in his house and we cannot send either.

Not sure what to do.

He may have a port 25 block; happens to some Comcast users for various
reasons. Does the Covad provided email allow SMTP message submission through
port 587, or port 465?

 

[bjohnson]

i have had similar problems with outlook 2007. I use IMAP access to a
Email account (not gmail or hotmail etc) and have been sending and
receiving emails for the past 3 months with no problem. As of January
1st 2008 i can no long send mails. I am still receiving emails but
keep getting the error 0x80042109. Says i can not connect to your
outgoing SMTP email server. I checked to make sure that port 25 wasn't
being blocked on my end but then again if it was i wouldn't be
receiving emails either. On another note if i access this account
through exchange outlook web access i can send emails out. I am also a
comcast user. Thanks for any suggestions or help.

 

[N. Miller]

i have had similar problems with outlook 2007. I use IMAP access to a
Email account (not gmail or hotmail etc) and have been sending and
receiving emails for the past 3 months with no problem. As of January
1st 2008 i can no long send mails. I am still receiving emails but
keep getting the error 0x80042109. Says i can not connect to your
outgoing SMTP email server. I checked to make sure that port 25 wasn't
being blocked on my end but then again if it was i wouldn't be
receiving emails either.

Wrong. Port 25 has nothing to do with receiving email. By RFC 2821, port 25
is designated for "mail transfer". Most E-mail Service Providers initially
also use it for message submission. However, because outbound 25 can be used
with *any* SMTP server, not just message submission servers, spamming
Trojans infecting HSI customer computers, can jam spam to gateway mail
servers. As a consequence, more ISPs are blocking outbound port 25 access to
their residential customers, and more ESPs are providing access either on
RFC 2476 designated Message Submission port 587, or Cisco designated Message
Submission port 465 (some, such as Gmail, offer both).

Receiving email is done using port 110 (non-secure), port 995 (POP3 with
SSL), or port 993 (IMAP with SSL).

On another note if i access this account through exchange outlook web access
i can send emails out. I am also a comcast user. Thanks for any suggestions
or help.

Comcast uses a hardware device to detect SMTP activity on outbound port 25.
If that exceeds a specific threshold, they push a port 25 block modem
configuration file onto their customers' cable modems. I don't know what the
file has (you should be able to view it in the modem GUI pages), but an easy
test for a port 25 block is to try to Telnet into the Message Submission
server on port 25. Looks like this:

| C:\Documents and Settings\User>telnet smtp.comcast.net 25
| Connecting To smtp.comcast.net...
| 220 OMTA02.westchester.pa.mail.comcast.net comcast ESMTP server ready
| quit
| 221 2.0.0 OMTA02.westchester.pa.mail.comcast.net comcast closing connection
|
|
| Connection to host lost.

If you get this instead:

| C:\Documents and Settings\User>telnet smtp.comcast.net 25
| Connecting To smtp.comcast.net...
| Could not open connection to the host, on port 25:
| Connect failed

You have an outbound port 25 block on your cable modem.

 

[bjohnson]

Wrong. Port 25 has nothing to do with receiving email. By RFC 2821, port 25
is designated for "mail transfer". Most E-mail Service Providers initially
also use it for message submission. However, because outbound 25 can be used
with *any* SMTP server, not just message submission servers, spamming
Trojans infecting HSI customer computers, can jam spam to gateway mail
servers. As a consequence, more ISPs are blocking outbound port 25 access to
their residential customers, and more ESPs are providing access either on
RFC 2476 designated Message Submission port 587, or Cisco designated Message
Submission port 465 (some, such as Gmail, offer both).

Receiving email is done using port 110 (non-secure), port 995 (POP3 with
SSL), or port 993 (IMAP with SSL).


Comcast uses a hardware device to detect SMTP activity on outbound port 25.
If that exceeds a specific threshold, they push a port 25 block modem
configuration file onto their customers' cable modems. I don't know what the
file has (you should be able to view it in the modem GUI pages), but an easy
test for a port 25 block is to try to Telnet into the Message Submission
server on port 25. Looks like this:

| C:\Documents and Settings\User>telnet smtp.comcast.net 25
| Connecting To smtp.comcast.net...
| 220 OMTA02.westchester.pa.mail.comcast.net comcast ESMTP server ready
| quit
| 221 2.0.0 OMTA02.westchester.pa.mail.comcast.net comcast closing connection
|
|
| Connection to host lost.

If you get this instead:

| C:\Documents and Settings\User>telnet smtp.comcast.net 25
| Connecting To smtp.comcast.net...
| Could not open connection to the host, on port 25:
| Connect failed

You have an outbound port 25 block on your cable modem.

i tested the and got the connect failure on port 25. i further read on
http://www.lockergnome.com/usrbingeek/2007/04/12/comcast-blocking-port-25/
about switching to port 587 etc for outgoing. But no such luck for my
issues so far. thanks for the help so far. This is very frustrating
for something that has been working fine for the past 3 months.

 

[N. Miller]

i tested the and got the connect failure on port 25. i further read on
http://www.lockergnome.com/usrbingeek/2007/04/12/comcast-blocking-port-25/
about switching to port 587 etc for outgoing. But no such luck for my
issues so far. thanks for the help so far. This is very frustrating
for something that has been working fine for the past 3 months.

Comcast also accepts connections to 'smtp.comcast.net' using port 465 with
SSL. Might give that a try.

 

[M.Mathews]

I have been struggling with this issue for over a month now...THANK YOU for
the explanation...Fixed my problem in a snap.