@Gaspard DHautefeuille, could you please list steps in Thunderbird UI, with a concrete and specific domain, where this fails, so that there's at least one test case? As I said, these are exceedingly rare.
Bug 1799635 Comment 7 Edit History
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@Gaspard DHautefeuille, could you please list steps in Thunderbird UI, with a concrete and specific email domain, where this fails, so that there's at least one test case? As I said, these are exceedingly rare.