Last Thursday, ATT.net and scbglobal.net stopped delivering our emails to their user users accounts (we are a SaaS app who caters to school PTA's and several of our customers said that none of these parents were receiving our messages). Mandrill showed all these emails as delivered and no bounce messages. After spending "many" hours researching spam lists,etc, as well as almost 4 hours on the phone with ATT and sbcglobal tech support on Monday, I decided to email Mandrill on Tuesday and ask for help. I have posted their reply below.
The upshot is that their entire IP range was blocked by all ATT related email accounts from last Thursday until this Tuesday and they (Mandrill) did not notify users or disclose this information on their website. I subsequently emailed them and asked about future notifications in such a situation and they replied that an updated bounce processer will resolve the issue. I replied that it would not. It would correctly show that these emails had bounced but would not identify that the issue was at the Mandrill level and not with our account.
Similarly, about a year ago we had a situation where Cablevision was bouncing 20% of our emails consistently. Didn't matter if a blast included 40 Cablevision related addresses or 200. It took me several months of emails and phone calls but finally was told that they throttle back all emails routed through Mandrill due to the amount of spam that comes through their service. Since I use a single outgoing email address, and dedicated IP, Cablevision moved my IP to a different spam filter pool and I haven't had a problem since.
Not sure if a competing service like SendGrid would be any better but, since we send between 300,000 and 700,000 emails a month we are exploring other options.
Just wanted to make sure the Alpha community was informed.
Jay
*************************************************************************************************************************
Brett (Mandrill Support)
Aug 25, 10:41 AM
Hi Jay,
Thanks for reaching out! Unfortunately, it looks as though ATT blocked our entire IP range last week - this isn't related to your delivery, specifically, nor to your Dedicated IP. Our Delivery and Compliance teams have been working with ATT since Wednesday - it seems as though this block was never intended, and ATT initially indicated that this would be removed over the weekend, but we're unfortunately still seeing rejected emails.
We have an open dialogue with ATT and are working to get this block removed as soon as possible, but in the meantime we're receiving the following response when attempting to deliver emails to any ATT-affiliated domains (att.net, bellsouth.net, sbcglobal.net, etc):
521 xxx.xxx.xxx.xxx blocked by ldap:ou=rblmx,dc=att,dc=net Error - Blocked for abuse. Contact [email protected].
As for the "Delivered" status - Whenever we send an email, we immediately mark it as "Delivered" in the Outbound Activity page. However, when you check on the status of this Delivery by clicking "Delivered," we will show no smtp events until we receive a response from the recipient server (and index that response, which normally can take several minutes). Once this happens, you'll be able to see the exact message that we received, as well as the time stamp and the IP addresses of the sending and receiving server.
In general, our systems will process any Bounce Message and then report it to you in "Outbound Activity". However, our current bounce processor will occasionally come across a non-standard response (such as the one above) that it's unable to properly parse. In this case, our system will fail to acknowledge that message as a bounce, and will instead report "no smtp events" when you check on the status of that email. We're testing an upgraded bounce processor which should help to alleviate this issue.
The upshot is that their entire IP range was blocked by all ATT related email accounts from last Thursday until this Tuesday and they (Mandrill) did not notify users or disclose this information on their website. I subsequently emailed them and asked about future notifications in such a situation and they replied that an updated bounce processer will resolve the issue. I replied that it would not. It would correctly show that these emails had bounced but would not identify that the issue was at the Mandrill level and not with our account.
Similarly, about a year ago we had a situation where Cablevision was bouncing 20% of our emails consistently. Didn't matter if a blast included 40 Cablevision related addresses or 200. It took me several months of emails and phone calls but finally was told that they throttle back all emails routed through Mandrill due to the amount of spam that comes through their service. Since I use a single outgoing email address, and dedicated IP, Cablevision moved my IP to a different spam filter pool and I haven't had a problem since.
Not sure if a competing service like SendGrid would be any better but, since we send between 300,000 and 700,000 emails a month we are exploring other options.
Just wanted to make sure the Alpha community was informed.
Jay
*************************************************************************************************************************
Brett (Mandrill Support)
Aug 25, 10:41 AM
Hi Jay,
Thanks for reaching out! Unfortunately, it looks as though ATT blocked our entire IP range last week - this isn't related to your delivery, specifically, nor to your Dedicated IP. Our Delivery and Compliance teams have been working with ATT since Wednesday - it seems as though this block was never intended, and ATT initially indicated that this would be removed over the weekend, but we're unfortunately still seeing rejected emails.
We have an open dialogue with ATT and are working to get this block removed as soon as possible, but in the meantime we're receiving the following response when attempting to deliver emails to any ATT-affiliated domains (att.net, bellsouth.net, sbcglobal.net, etc):
521 xxx.xxx.xxx.xxx blocked by ldap:ou=rblmx,dc=att,dc=net Error - Blocked for abuse. Contact [email protected].
As for the "Delivered" status - Whenever we send an email, we immediately mark it as "Delivered" in the Outbound Activity page. However, when you check on the status of this Delivery by clicking "Delivered," we will show no smtp events until we receive a response from the recipient server (and index that response, which normally can take several minutes). Once this happens, you'll be able to see the exact message that we received, as well as the time stamp and the IP addresses of the sending and receiving server.
In general, our systems will process any Bounce Message and then report it to you in "Outbound Activity". However, our current bounce processor will occasionally come across a non-standard response (such as the one above) that it's unable to properly parse. In this case, our system will fail to acknowledge that message as a bounce, and will instead report "no smtp events" when you check on the status of that email. We're testing an upgraded bounce processor which should help to alleviate this issue.
Comment