[ale] Blacklisted mail server?

[Nathan J. Underwood]

Everyone,

	I apologize for the (long) delay in getting back to you on this.  At 
any rate, I found that Cbeyond does not provide any reverse dns (by 
default).  Since the client wasn't using them for DNS, I had to use the 
online help to request PTR entries for each of the external IP's (rather 
than add them myself).  I filled out the request form, and within 12 
hours the new records were active and the client can now send emails out 
without fail (thus far).

--

registered linux user # 73046

Nathan J. Underwood

nathan.underwood at cybertechcafe.net
Proverbs 16:11

alelist at cxdonline.com wrote:
>>A client of mine has recently started using Cbeyond as their ISP.  Since
>>the cutover, they've had problems sending emails to random domains.
>>After digging around a bit, I've found that they seem to be blacklisted.
>>    The error messages that the users are getting were pretty generic,
>>so I started digging further.  My first move was to ping the server
>>reported as the primary MX for the recipient (got a response).  I then
>>tried to telnet to the mail server (i.e. telnet mail.server.net 25), and
>>got an immediate connection refused.  I then tried the same exercise
>>from my ip (not blacklisted), and was able to connect.  They're not an
>>open relay, and I've not been able to find any lists that their listed
>>on.  Anyone got any suggestions on where to look next?
>>
> 
> This sounds like a problem I recently had with GoDaddy blocking e-mails
> sent from my server to some of GoDaddy's customers. It seems that the ISPs
> are starting to block all port 25 traffic to their servers except for
> traffic coming from other ISPs.
> 
> The fix was to set my ISP's mail server as a smart host in my sendmail
> config. and route my outgoing e-mail though my ISP's e-mail server.
> GoDaddy will accept e-mail from my ISP.
> 
> Steve