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Author Topic: New Comcast issue!  (Read 47863 times)

pkale

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New Comcast issue!
« on: April 28, 2011, 05:38:08 AM »
 Hello everyone!  :)

We are having issues with any emails that we are sending to our Comcast customers. Just wondering if anyone else is facing something similar.

We used to deliver around 300,000 emails everyday consistently using a few IPs. We have Domain Keys, SPF records, Reverse DNS in place as well as unsubscribe links and bounces/unsubscribes are handled on the same day. The complaint rates have always been minimal and reputation around average.

On this particular 'doomsday', all our emails started being delivered into Spam folder. No blocks, no blacklists. Only a header X-CAA-SPAM: F00001 added to our emails.

Even our brand new IPs with a sending rate of around 100 emails to warm them up landed in spam within seconds (!!) of using them.  ??? Has anyone at all experienced something like this before? Any suggestions would be much appreciated.

Cheers!  :)
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lcsunshine

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Re: New Comcast issue!
« Reply #1 on: April 28, 2011, 09:17:22 AM »
How many bounces have you had delivering to comcast or connection errors? Have you looked at the VMTA Response Code for the comcast.net domain.

It is possible that you may have delivered to many recipients which have generated errors ie. User over quota / mailbox unavailable etc.

Do you have a pattern lists setup and backoff mode configured to respond to SMTP error response codes etc. Reference: http://www.port25.com/forum/index.php?topic=88.0

I know Comcast also uses sender score to determine how and if your emails are to be delivered. Check your IPs here: https://www.senderscore.org/

Let me know what you turn up.

Regards
Don

 
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nickphx

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Re: New Comcast issue!
« Reply #2 on: April 28, 2011, 08:40:36 PM »
Could be your sending domain or domains used in your links.
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pkale

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Re: New Comcast issue!
« Reply #3 on: April 29, 2011, 04:07:38 AM »
Hey all,

Firstly, thanks for your reponses!

Nick, even I checked the same first; we have multiple domains for the same and they work just fine if used with other IPs. But only for a bit. We even use URL shorteners earlier. We stopped that as well just to make sure that's not the cause.

Don, the bounces are very negligible as we clean the data for bounces/unsubs before we start sending. No errors in connection or maillog too. The list is clean and almost all mails get accepted for delivery.
Maybe our old IPs had average reputation, but the new have no history of mailing and reputation 100. Even these landed in spam after sending 100 emails (all delivered). Urrgh :o

Thanks again.
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lcsunshine

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Re: New Comcast issue!
« Reply #4 on: April 29, 2011, 10:59:33 AM »
Pkale

I have a old comcast.net email account I use for testing only. If you want and feel comfortable shoot me a test email of the content you are sending to: ddavanzo3 [at] comcast.net

I'd like to analyze your email headers. They can be cryptic sometimes but I have honed my skills when it comes to interpreting / reading them.

It can be something as simple as your IP's being in a bad neighborhood or someone in a different subnet on the same IP Netblock spamming. Many of these ISP's filters and admin will "go the range" / scrutinize a entire netblock cause of one jerk spamming on another subnet.

Let me know if you want my help further.

If you decide to send a test email let me know the subject / from name so I can be on the lookout for it.

Regards
Don
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