Thanks. I will email you at support about at least one situation that does not fit this - namely, an email address that already had an account was sent a confirmation email after requesting membership via email. (Before doing that, I will run the test again. I think I ran it several times already but will do that again to be sure.)
In general, why are the two sequences - request join via email and request join via the web - so different? It is confusing to moderators (at least this one:). I would assume (and was assuming) that in both cases, the confirmation email and the pending subscription notice are sent immediately upon the join request. Yet you say here that in the case of requesting via email, they have to confirm before receiving the notice. Is there a reason why? I ask because it would give me some guidance about when to query them outside the system about whether they've received the pending notice. And also, if it is at all possible, it would be more helpful and clear if in both cases, they were done the same way.
Also: could you also possibly add to these sequences the "appropriate messages to moderators" that you said you've left out here? I sometimes have no idea what's going on when I see a pending member without an NC, or with an NC. I look in their email delivery history to see what they've last been sent (but that is often less than illuminating). Sometimes I will immediately "resent" the pending subscription notice, but now I see that in some cases, they were not SUPPOSED to have been sent it yet. I would like to know precisely when in these sequences the "appropriate message to moderators" are sent.
Finally: I understood, perhaps wrongly, that in a premium group, once we approve the membership it also confirms them. I have some memory of when you made that change. Yet recently, there have been several members we've approved who are still NC. Did this change, or am I misremembering?
Messages are the sole opinion of the author, especially the fishy ones.
I wish I could shut up, but I can't, and I won't. - Desmond Tutu