On Sat, Jul 25, 2020 at 06:41:59PM -0700, Kevin J. McCarthy wrote:
The past few days I've started to see a number of people unsubscribed from mutt-dev because their mail servers are bouncing DMARC-failing emails received from mutt-dev.
Maxim and Tom have been helpfully taking a look. It appears to be a combination of DMARC p=reject policy, and a DKIM "simple" Canonicalization Algorithm policy. The mailing list or one of the hops inside OSUOSL does appear to be touching the header/body in small ways that cause the "simple" algorithm to fail.
For example, comparing my copy in sent vs mutt-dev, I noticed one of my emails had the content-type folding WSP was changed from a tab to a space.
In the mean time, I have turned on a Mailman feature that will wrap emails from domains with a DMARC p=reject policy. I am quite open to other suggestions, but for now want to stop mass unsubscribes due to DMARC p=reject bounces.
-- Kevin J. McCarthy GPG Fingerprint: 8975 A9B3 3AA3 7910 385C 5308 ADEF 7684 8031 6BDA
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