Perhaps this is a test case for the same (already fixed?) bug?
vi.bug3 (message/rfc822), 40 bytes, created by Ronald F. Guilmette on 2020-05-16 23:23:34 UTC
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Creator: Ronald F. Guilmette
Created: 2020-05-16 23:23:34 UTC
Size: 40 bytes

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Attachments on bug 202290: 165486 | 165487 | 214569