Start and End Date/Time (UTC):
05:13 February 5th, 2020 - 11:30 February 5th, 2020
Limited Release, America East, America East 2, America West, America West 2, Spanish (Español), Australia / New Zealand, UK (United Kingdom), UK2 (United Kingdom 2) and UK Limited Release (United Kingdom).
On the evening of February 11th, during a scheduled maintenance, we added new infrastructure and security measures to our mail clustering environment in our LON and PHL Data Centers. While our testing was successful after the change, we started to receive reports several hours later of email delays and processing issues. At approximately 6:30 AM Eastern, we made the decision to revert all changes made the evening before to give us more time for research and to temporarily resolve the email processing issues. After we reverted the change, there was a backlog of emails to be processed that took approximately an hour to catch up.
After further investigation, we discovered that our emails were being greylisted due to the new IP addresses used to send the emails from the Autotask PSA. Although the new IPs were within our published range they had no established IP reputation and were therefore greylisted by some recipients’ filtering providers. We researched the greylisting issue and made the decision to stay with the established external mail IPs. The following night we re-implemented the new infrastructure and security measures but maintained the established external mail IPs.