Three weeks ago, starting with TidBITS #1574, Apple’s iCloud Mail servers decided that there was something about the TidBITS issues they didn’t like and started rejecting issues with this error:
SMTP Errors: 554 5.7.1 [CS01] Message rejected due to local policy. Please visit https://support.apple.com/en-us/HT204137
It took our support expert Lauri Reinhardt a little while to piece together questions from subscribers and her own tests. Once she had assembled a coherent picture of what was going on, I reported the problem to iCloud Mail support. Two days later, the iCloud Mail team told me that they had made appropriate changes to resolve the delivery problems. My tests confirmed that, but there was more to do.
The problem was that Sendy, our mailing list management software, had marked over 300 iCloud users as bouncing. (That may seem like a lot, but we have well over 5000 iCloud subscribers all told. I can’t explain why such a small percentage bounced.) I have reset all the affected icloud/me/mac.com addresses, so in theory, everyone who failed to receive the last issue or three should get TidBITS #1577 on 30 August 2021.
I say “in theory” because there are two other variables. First, if you subscribe from a custom email address that forwards to iCloud and doesn’t receive this week’s issue, you may still be affected; contact Lauri for help.
Second, Sendy gives us an interface for funneling messages to the Amazon Simple Email Service for the actual delivery. Amazon SES maintains a global suppression list that prevents email from going out to an address that has recorded a hard bounce for any Amazon SES user. We can remove addresses from Amazon SES’s global suppression list when we know they’re good and have fixed whatever problem was causing the bounces. But we have to do that one address at a time, with an image CAPTCHA, and there’s no way to query the list or even know if a removed address was on the list—all that Amazon SES tells us is that the address was removed if it was on the list. Doing that one by one with over 300 addresses would be a royal pain.
Amazon’s user guide says that Amazon SES automatically removes addresses from the global suppression list, increasing the amount of time an address stays on the list after each bounce. The longest an address will remain on the list is 14 days, and since TidBITS subscribers wouldn’t have bounced more than three times, I’m hoping Amazon SES has already removed all those addresses. If not, it should happen before TidBITS#1578 comes out on 6 September 2021.
With any luck, then, this situation will go away either this week or next. Our apologies for any confusion it may have caused—it’s yet another example of how systemic anti-social behavior by some (spammers) causes ongoing headaches for the rest of us.