The discussion addresses the warning introduced in Discourse 2026.1.5 regarding the aws_sns_topic_arn_allowlist setting. Dannii reports the alert stating that bounce notifications will be rejected until legitimate SNS topic ARNs are allowlisted, noting a lack of documentation in the changelog. Jonathan5 explains that this setting requires users to add the Amazon Resource Names (ARNs) of their SNS topics for bounces and complaints, which can be found in the AWS SNS console. By entering these ARNs into the Discourse setting, the warning disappeared, confirming it as the intended fix.
jeff_y provides further context, explaining that the setting allows Discourse to receive bounce notifications from Amazon SES via SNS. However, they question whether this applies to sites that use SES only for sending and handle incoming email/bounces via separate tools like mail-receiver or their own MX records, rather than SES inbound endpoints. Dannii expresses frustration with the lack of official explanation for the new warning but notes that ignoring the alert since July resulted in no operational issues for their setup.
Since updating to 2026.1.5, I now see this site advice:
The server is configured to send emails via Amazon SES but you haven’t allowlisted any SNS topic ARNs. Bounce notifications will be rejected until you add the legitimate ARN to aws_sns_topic_arn_allowlist.
I can’t find any information about this setting though.
On the Amazon SNS console I already had two “Topics” set up. I have only hazy memories of setting up SES. It must have been in the relevant Discourse instructions. It’s also mentioned in this recent topic: How do I properly configure the AWS SNS topic ARN allowlist?.
One was for bounces and one for complaints, and there were ARNs for each in the format arn:aws:sns:eu-west-1:111111111111:DiscourseBounces. I put both of these ARNs into the aws_sns_topic_arn_allowlist Discourse setting and the warning doesn’t appear any more. I hope that means I did the right thing…
According to this, it sounds like the setting is for Discourse learning about bounces that were received by Amazon after sending via SES.
However, I’m using SES just to send messages for forum.example.com, and I’m using mail-receiver to receive replies and bounces. I think the warning message in the Discourse dashboard only applies to people receiving replies & bounces via SES, right? Not for those with an MX record going to our own server?