So about a month or so ago, Salesforce released a new list of IP addresses that needed to be whitelisted. See the knowledge article below for a full list of the IP addresses
We did this when they sent out the notification. On 12/28 something occurred with a group of their IP addresses that caused some sever implications for our org. It seems as though when the IPs were registered, they were not done so correctly and were not showing up as SF owned IPs, but rather as an 'unknown'. Our org, as well as many other companies have some pretty strict spam filters that bounce these unknown IPs as a possible threat.
This caused huge issues. Our quote approval processes were all stalled as the approval emails were being bounced. We had many emails bounced that bounced back to our Email2Case address which opened many cases (over 100k in 3 days). Basically any system generated email from SF was being bounced as being sent from a blacklisted IP.
We have been working with SF for the past day and a half, and they have temporarily moved us from the IP ranges in question, but they will not admit fault in having their IPs blacklisted (not surprising). They fully admitted to us that there were many other customers that has this same issue.
I was just wondering if this effected anyone else and if they were able to do something themselves to mitigate this or were they forced to wait for Salesforce support to unravel the mess on their end, since that is always quick and painless [sarcasm]