dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
4321
share rss forum feed


Gork
Ou812ic

join:2001-10-06
Bountiful, UT

[E-mail] SMTP server down?

I use Comcast's SMTP server at smtp.comcast.net to send my emails. Without making any changes on my end I can no longer send emails; Outlook is unable to connect to the server.

I can't find any information as to the server being down, or a maintenance window or anything similar. I'm trying to ascertain if this is a global issue or just an issue with my connection/account. Is anyone else currently in/effectively using this SMTP server?

I called Comcast but they said their system is down so they cannot access my account. Why they need to access my account to let me know if their SMPT service is down is beyond me. /sigh

Fwiw I did post in the support forum on this board as well. (Comcast Direct.)



Gork
Ou812ic

join:2001-10-06
Bountiful, UT

I get 100% loss for pings either smtp.comcast.net or pop.comcast.net so either they're down or Comcast has changed something and I haven't been advised of the change... ??



NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

3 edits

1 recommendation

reply to Gork

Are you using port 25? If so, Comcast no longer responds to port 25 requests to smtp.comcast.net. They do however, allow you to use port 587 (with or without TLS):

webhost:/ # telnet smtp.comcast.net 25
Trying 2001:558:fe14:70::30...
Connected to smtp.comcast.net.
Escape character is '^]'.
554 omta06.westchester.pa.mail.comcast.net comcast Port 25 not allowed - 
http://customer.comcast.com/help-and-support/internet/email-client-programs-with-xfinity-email/
Connection closed by foreign host.
webhost:/ # telnet smtp.comcast.net 587
Trying 2001:558:fe14:70::30...
Connected to smtp.comcast.net.
Escape character is '^]'.
220 omta18.westchester.pa.mail.comcast.net comcast ESMTP server ready
quit
221 2.0.0 omta18.westchester.pa.mail.comcast.net comcast closing connection
Connection closed by foreign host.
 

FWIW, I get the port 25 reject message because I have a business class account. I suspect that a residential account (that has port 25 blocked) would just get a time out.

You might want to read this related thread: »Comcast decides to block port 25 IN and OUT with no notice..
--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

1 edit
reply to Gork

said by Gork:

I get 100% loss for pings either smtp.comcast.net or pop.comcast.net so either they're down or Comcast has changed something and I haven't been advised of the change... ??

Does your connection support IPv6? It appears that Comcast is no longer responding to IPv4 pings on those two hosts, but they do respond to IPv6.

webhost:/ # ping -c4 pop.comcast.net
PING mail.g.comcast.net (68.87.26.158) 56(84) bytes of data.
 
--- mail.g.comcast.net ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3024ms
 
webhost:/ # ^C
webhost:/ # ping6 -c4 pop.comcast.net
PING pop.comcast.net(pop3.westchester.pa.mail.comcast.net) 56 data bytes
64 bytes from pop3.westchester.pa.mail.comcast.net: icmp_seq=1 ttl=56 time=37.3 ms
64 bytes from pop3.westchester.pa.mail.comcast.net: icmp_seq=2 ttl=56 time=36.6 ms
64 bytes from pop3.westchester.pa.mail.comcast.net: icmp_seq=3 ttl=56 time=36.1 ms
64 bytes from pop3.westchester.pa.mail.comcast.net: icmp_seq=4 ttl=56 time=37.1 ms
 
--- pop.comcast.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 36.179/36.833/37.364/0.505 ms
 
webhost:/ # ping -c4 smtp.comcast.net
PING smtp.g.comcast.net (68.87.26.155) 56(84) bytes of data.
^C
--- smtp.g.comcast.net ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3022ms
 
webhost:/ # ping6 -c4 smtp.comcast.net
PING smtp.comcast.net(2001:558:fe14:70::30) 56 data bytes
64 bytes from 2001:558:fe14:70::30: icmp_seq=1 ttl=56 time=37.6 ms
64 bytes from 2001:558:fe14:70::30: icmp_seq=2 ttl=56 time=37.4 ms
64 bytes from 2001:558:fe14:70::30: icmp_seq=3 ttl=56 time=38.6 ms
64 bytes from 2001:558:fe14:70::30: icmp_seq=4 ttl=56 time=36.3 ms
 
--- smtp.comcast.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3005ms
rtt min/avg/max/mdev = 36.346/37.545/38.693/0.865 ms
 

--
A well-regulated militia, being necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed.

When governments fear people, there is liberty. When the people fear the government, there is tyranny.


Gork
Ou812ic

join:2001-10-06
Bountiful, UT

4 edits

I appreciate your help, NetFixer See Profile. I saw that other post but jumped to the conclusion they were blocking customers' mail servers only on that port. I now understand the thread is about everything on port 25 being blocked, even to their own mail servers. I receive my bills from Comcast online only and do not recall ever being notified of this change. It also seems important enough it should be easily accessible information on their web pages, ESPECIALLY in a message once the customer logs into their account!

I've had so many problems with Comcast lately and this is just one more.

In answer to your question about IPv6, Comcast doesn't appear to offer it in my service area yet. I have a compatible router and modem (just purchased my own cable modem) but no go.

Again, my sincere thanks. Fwiw I tried port 465 as well, per the letter from Comcast others posted in the link you shared, but it didn't work. 587 did.

Oh and yes, my account is a residential account and the ping attempt (ping smtp.comcast.net) did time out. Thank God the company I purchase email hosting from uses port 587...

EDIT:
I was able to use port 465 once I enabled SSL encryption.


Stu Pidaso

join:2006-10-12
Greenwood, IN
kudos:2

Just curious as I never saw mention of it in your post. Is this for a comcast.net email address or for an email address you have with someone else. If it is the latter this info would have helped in trouble shooting. I only ask because your last post sounded like that was the case.


luckmann

join:2004-06-27
Albuquerque, NM
Reviews:
·Comcast

1 recommendation

reply to Gork

If you don't have IPv6 native yet (I don't since i am on a Cisco CMTS). You can use Comcast 6to4 tunnel. Depending on your router if you have IPv6 set to automatic detect it will pick up the nearest tunnel. The tunnel is a bit slower than native but it works.



NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:11
Reviews:
·SONIC.NET
·Pacific Bell - SBC
reply to Gork

said by Gork:

I appreciate your help, NetFixer See Profile. I saw that other post but jumped to the conclusion they were blocking customers' mail servers only on that port. I now understand the thread is about everything on port 25 being blocked, even to their own mail servers. I receive my bills from Comcast online only and do not recall ever being notified of this change. It also seems important enough it should be easily accessible information on their web pages, ESPECIALLY in a message once the customer logs into their account!

I've had so many problems with Comcast lately and this is just one more.

I went through the same eleven years ago, when SBC moved to block port 25 to their customers. Despite that SBC sent out an e-mail notice (I still have my copy), many customers claim that they did not receive notification.

I don't usually check web sites for other ISPs, and my experience with accessing Comcast from a non-Comcast account for technical issues, lately, is that it isn't easy to navigate; but Comcast has long offered access via port 465, with SSL, for customers who might be on the road, and attempting access from a different ISP, one which blocked port 25 to servers other than their own. Port 25 blocking is ubiquitous among U.S. ISPs; Comcast was the last holdout for at least the last six, or seven years.

Thank God the company I purchase email hosting from uses port 587...

All the free ESPs that offer SMTP access, and the larger pay services as well, offer either port 465 (which normally requires SSL), or port 587 (recommended by RFC since 1998; and sometimes requiring TLS, per that RFC); or both (Gmail is both).

EDIT:
I was able to use port 465 once I enabled SSL encryption.

That is just about standard.

Just a history of the RFCs governing "Mail Transfer" (server-to-server) and "Message Submission" (user-to-server) since SMTP was first defined in 1982:

»tools.ietf.org/html/rfc821 (August, 1982) Mail Transfer
»tools.ietf.org/html/rfc822 (August, 1982) Mail Transfer
»tools.ietf.org/html/rfc2476 (December, 1998) Message Submission
»tools.ietf.org/html/rfc2821 (April, 2001) Mail Transfer
»tools.ietf.org/html/rfc2822 (April, 2001) Mail Transfer
»tools.ietf.org/html/rfc4409 (April, 2006) Message Submission
»tools.ietf.org/html/rfc5321 (October, 2008) Mail Transfer, Current
»tools.ietf.org/html/rfc5322 (October, 2008) Mail Transfer
»tools.ietf.org/html/rfc6409 (November, 2011) Message Submission, Current
»tools.ietf.org/html/rfc6854 (March, 2013) Mail Transfer, Current

Comcast is probably the last major U.S. ISP to come into compliance with RFC 6409.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


Gork
Ou812ic

join:2001-10-06
Bountiful, UT

1 edit
reply to Stu Pidaso

said by Stu Pidaso:

Is this for a comcast.net email address or for an email address you have with someone else.

I'm actually referring to sending email through the Comcast sever. I use another company for receiving emails which is integrated with my domain name for other services as well.

said by NormanS:

All the free ESPs that offer SMTP access, and the larger pay services as well, offer either port 465 (which normally requires SSL), or port 587 (recommended by RFC since 1998; and sometimes requiring TLS, per that RFC); or both (Gmail is both).

Yes, in trying to set up an account to send through my email hosting company I learned they no longer allowed access through port 25 either, and same as with Comcast, they never bothered to let me know. So this was a learning experience...

Thank you for all your additional information as well...

said by luckmann:

You can use Comcast 6to4 tunnel.

I've read about this but haven't tried to use it yet. I also have more learning to do with regard to IPv6 and how it's going to impact my network setup. I've had a difficult time figuring out, as well, how Comcast is going to implement customer addressing for IPv6 so I can be more ready when they do go live in my area. I'm also concerned my router won't handle IPv6 very well - it's been a recent addon with a fw update and it's not getting rave reviews.

It's been a good 6 months since I spent any time looking into this and need to get it back in check.


NetDog
Premium,VIP
join:2002-03-04
Parker, CO
kudos:77
reply to Gork

If you have questions about Comcast IPv6 program feel free to ping me the questions.. or just post a new subject asking them. I will answer what I can..


luckmann

join:2004-06-27
Albuquerque, NM

1 recommendation

reply to Gork

You can also use the Comcast forums... ComcastTuska has been good about answering questions. He can determine what IPv6 services are available to you. There is also a tutorial about 6to4 (several actually) that you can look at.



NetDog
Premium,VIP
join:2002-03-04
Parker, CO
kudos:77
Reviews:
·Comcast

said by luckmann:

You can also use the Comcast forums... ComcastTuska has been good about answering questions.

NetDog = ComcastTuska

Thanks for the compliment


Gork
Ou812ic

join:2001-10-06
Bountiful, UT

said by NetDog:

NetDog = ComcastTuska

hehe Sawheet!


56885201
Ain't Nothin' But A Hound Dawg
Premium
join:2005-05-01
Dawg House

said by Gork:

said by NetDog:

NetDog = ComcastTuska

hehe Sawheet!

I guess that proves the adage that on the Internet, nobody knows that you are a dawg unless you tell them you are a dawg.
--
Some days you're the dog; some days you're the hydrant.