In all of them, I'm the actor, but they specify "Self Mail" as the (a) reason for voiding.
I do have "self mail" disabled, so it might be taking that?

This sounds like the expected behavior, yes. If you look at mail which you didn't send (e.g., find this mail in /mail/), I'd expect it isn't voided and isn't marked "self mail".

(I might be misunderstanding the point of confusion? It sounds like you've disabled self-mail, this is all self-mail, and it's being correctly voided because it's self-mail?)

I think all of those are not self-mail - they are all have "TO" as other users than myself.

mm, 184911 does show me as the only "X-Phabricator-To"; but 219192 has you and Chad as "X-Phabricator-To" (And my phid isn't in the Headers page).

I can't actually see them, let me go pull up the console.

My last comment added 3 messages in my outbox:

• 229036 - from avivey to avivey
• 229037 - from avivey to epriestley, shows this:

• 229038 - from avivey to somebody else, also shows the same ui.

If I understand the mail visibility, you should be able to see 229037
(PHID-MTAM-qfsqnqkebrkuaohcacsg), because it's "to" you?

223663 is you adding a comment to Conpherence.
184911 is you moving a task on a workboard.
219192 is you attaching a task to a revision.

"Self-mail" is mail where you are the actor taking the action, so this all looks like self-mail to me -- it doesn't care who is on "To".

219192 wouldn't have been sent to you anyway (you weren't subscribed/reviewer/etc on the diff, and DifferentialTransactionEditor does not include the actor on mail, which is a bug), but it super extra wasn't sent to you because it was also self mail. The reasons for voiding didn't actually have an effect (obviously, after the first one voids the mail, the others can't really do much), they're just things you'd have to fix if you wanted to receive the mail.

The "Delivery" tab is specific to the viewer, not the mail. There's no way to see see why mail was or wasn't delivered to other users.

That is, "Delivery" is "delivery to you, the viewer". Maybe that's what's unclear?

It's definitely a little surprising that "Outbox > Delivery" is describing a sort of hypothetical scenario that assumes you were a recipient in the first place.

(But we don't currently know if you came from the inbox or outbox when looking at a mail.)

Maybe we could add a "you weren't a recipient in the first place" reason which has priority over the other reasons, and make the text on the page more clear. Or just remove "Outbox" completely, I'm not sure it's really useful.

It's definitely a little surprising that "Outbox > Delivery" is describing a sort of hypothetical scenario that assumes you were a recipient in the first place.

OK, this was the missing piece; I'm seeing a replay of the (current?) rules about this message, if it were addressed to me?
That's complicated.

Is the "Sent"/"Voided" label represents the actual message?

I'm seeing a replay of the (current?) rules about this message?

Nearly -- you're seeing a log of the rules running against an original "pre-message". Roughly, this happens:

• The mail begins life as one object with a list of recipients.
• We run all the rules on it to figure out who should really receive a copy.
• We set this log aside for later.
• Assuming metamta.one-mail-per-recipient is set, we split the original message into a lot of different objects.
• We attach a copy of the log to each of those objects.

So those three messages are really showing the same log, which records routing of the original pre-message.