Subscribers Soft Bouncing From a Particular Domain

My client is having this issue with all of their subscribers from cox.net addresses. What is the process to get this issue resolved? Should I call Cox and talk to their technicians? If so, what should I tell them?

roshodgekiss roshodgekiss, 6 years ago

Hi gssbrian, could you kindly contact our support team with your client's details? We'll look into this issue and assist you.


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bimcom, 6 years ago

@gssbrian - we've been having the exact same problem, with Cox.net rejecting (soft bounce) our newsletters, much to the chagrin of our subscribers. I'm now inundated with angry emails from subscribers wondering why they're not getting their regular Friday news.

FYI, I got word from CM that it's a relatively unfixable problem - so I contacted Cox directly, and they suggested that I email their "unblock" team to get our IP and/or sending domains unblocked.

No luck so far - 20% bounce rate on a campaign last Friday... it's KILLING us. Hoping to hear from the Cox people by tomorrow EOD.

Cheers and good luck.

roshodgekiss roshodgekiss, 6 years ago

Hi folks, I just had a chat with our sysadmin, who has confirmed that he's been in contact with the Cox.net operations team and has made the changes to our settings that they've requested. We're currently waiting on a response from Cox.net and hope to have this resolved shortly. Please keep us posted if further sends suffer from unusually high bounce rates and we'll stay on the case.


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BIMCOM2, 6 years ago

@Roshodgekiss - FYI, we're still having the same problem with Cox.net... just sent a campaign this week and had a 16% bounce rate, nearly all from Cox. My subscribers are seriously pissed, and our hands are tied.

I've sent two emails (the second one angry) to their "unblock@" email address. Never heard anything back from them on the first one, sent almost two weeks ago. This despite talking with their tech support people on the phone, and them telling me that I'd hear back from the "unblock@" email within 48 hours.

I'm going to try using a different email software to send to the same list, and see how it goes. I love CM and want to stick with you guys, but if I find that it's your IP's being blocked and that others (CC, RT, EC, etc.) can get through, I may have to change. Bummer!!

BIMCOM2, 6 years ago

@Roshodgekiss... FYI, I just got off the phone with Cox tech support. They recommended that you guys go to this site:

http://postmaster.cox.net/confluence/display/postmaster/Postmaster+Home;jsessionid=FDCE34E17BB312085F227051AE9CF1BD

He also said that the problem is "very likely" that Cox is trying to do a reverse DNS lookup and it's failing - so CM needs to make sure that a reverse DNS can be done for each email. (You may already be aware of that.)

Lastly, he said that the biggest company they work with for SPAM filtering is Spamhaus, and so CM should check to make sure that the sending IP's aren't listed on Spamhaus's blacklist.

I just had a 33% bounce rate on a campaign, with almost all of them Cox.net emails... so this is getting to be pretty painful.

Let's hope we can get it resolved!

roshodgekiss roshodgekiss, 6 years ago

Hi BIMCOM2, I just followed this issue up with our sysadmin and it looks like it may have been resolved as of Friday, 3 December. From the Cox.net team:

...I did some more in depth logfile digging and have found where your mailserver(s) IPs were being considered foreign IPs which have a much stricter rate limit than US IPs. I have updated our list of US IPs to include your mailservers IP ranges. I believe you should now see a better success rate in the delivery of your messages to cox.net accounts...

Please let us know if you run into further deliverability issues with Cox.net - hopefully this is the end of what's been a rather frustrating saga for all of us.


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BIMCOM2, 6 years ago

Thanks so much, Ros - I replied to your email as well. Campaign Monitor's customer service continues to be the very best in the industry. Please pass my 'thanks' on to the team there for the (loads of) efforts on this issue.

roshodgekiss roshodgekiss, 6 years ago

Thank you so much, I'm glad we've been able to help out here. Have certainly passed on your warm wishes to our tech team :)


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