On June 29, 2015, we saw a significant increase in customers reporting Zendesk email being delayed or refused for delivery at yahoo.com. After a detailed investigation, we have determined that email sent from a subset of our servers is being blocked as spam by Yahoo. The majority of the impact is being felt by customers in our EMEA data center.
We reported and then escalated this issue with Yahoo and are currently working directly with them to resolve the issue. We acknowledge this process is frustratingly slow and we know that email communication is a critical channel for you. We have made resolution of these delivery failures a top priority.
We do not yet have an ETA for resolution but are making progress working with Yahoo. We will continue to update you as we get more information. Please note that this problem only affects emails addressed to Yahoo mail domains (see below for a representative list of yahoo mail domains). This does not impact email addressed to other email domains (e.g. gmail, hotmail, etc).
Let us know if you have any followup questions by emailing us at firstname.lastname@example.org.
Which domains may refuse delivery?
Emails to the following domains may be refused for delivery or delayed until this issue is resolved:
rocketmail.com yahoo.ae yahoo.at yahoo.be yahoo.ch yahoo.co.id yahoo.co.il yahoo.co.in yahoo.co.jp yahoo.co.nz yahoo.co.th yahoo.co.uk yahoo.co.za yahoo.com yahoo.com.ar yahoo.com.au yahoo.com.br yahoo.com.co yahoo.com.hk yahoo.com.hr yahoo.com.mx yahoo.com.my yahoo.com.ph yahoo.com.sg yahoo.com.tr yahoo.com.tw yahoo.com.vn yahoo.cz yahoo.de yahoo.dk yahoo.es yahoo.fi yahoo.fr yahoo.gr yahoo.hu yahoo.ie yahoo.in yahoo.it yahoo.nl yahoo.no yahoo.pl yahoo.pt yahoo.ro yahoo.ru yahoo.se ymail.com