On 18 Jan 2021, at 04:12, Jochen Bern <jochen.b...@binect.de> wrote: > On 16.01.21 07:42, Ron Garret wrote: >> Because not every email has one. RFC5322 doesn’t require them. >> >> On Jan 15, 2021, at 6:30 PM, @lbutlr <krem...@kreme.com> wrote: >>> Why not simply use the message-id?
> (Also, you can legally have several e-mails with the same Message-ID in > your mailbox; e.g., someone addressed it to two aliases that both expand > to you, just to name one possibilty where *both* go through *sieve* as > well.) I delete duplicates before they are delivered to a mailbox. --
