Dan Caballero writes:
I've got a message that keeps getting re-queued to the /hyperkitty/spool/ folder. [...] "During handling of the above exception (expected atom at a start of dot-atom-text but found '[1db292f04b54496ab40544b0989a2122-JFBVALKQOJXWILKNK4YVA7CPNZSVMZLUPRCW2YLJNRKGK43UPRCXQ32TNV2HA===@microsoft.com]>')"
This is arguably a HyperKitty bug. The email package is correctly refusing to parse that as a Message-ID (it's been illegal syntax since RFC 822 if I remember correctly), but something, presumably HyperKitty, should catch the error and do something to sanitize it to message-id syntax. On the other hand, I never heard of a message trigger that exception before a couple months ago, so maybe it's the responsibility of spam filters.
I think when I ran into it, just moving it out of the HyperKitty archive queue fixed the queue. The client then put in a filter (it was indeed spam) in the MTA, and I haven't heard from them again.
In a later post you say that message came back, but I suspect it isn't the same message, but a new one likely from the same source.
I would say filter message-ids containing '[' either into /dev/null or a holding pen. Even Microsoft software knows how to generate syntacticly-valid message IDs, pretty sure that was not an @microsoft.com sender!
Steve