Am 17.03.22 um 03:40 schrieb Mark Sapiro:
The issue of more concern to me is when the subscription uses a deliverable address. The owner of that address receives this unwanted confirmation email which is bad enough, but then sometimes reports it as spam to her ISP which affects my server's reputation. But, so far, I don't do anything about that either.
As I'm a mail admin for a server whose users get lots of those misguided mails I'd say that the vast majority of them are not from mailing list signups but from web contact forms which automatically respond to entered contact requests with "Dear Polly liked your profile https://bit.ly/crap". I regularly report these as spam and expect website owners to disable automatic mails from such forms (I also advise our users who have their own websites to disable that, and strictly filter it on outgoing mail).
I would probably also report these as spam when coming from mailing lists subscription requests, and I would likewise advise you to send subscription responses only after a moderator checks and releases the subscription request. It can still happen that you send out somethin to someone who didn't subscribe, but you should be able to reduce the numbers significantly. I know this causes extra moderator work because you don't get the automated pre-filtering for deliverable addresses, so this is something where you need to weigh pros and cons for your particular situation.
Cheers, Hans-Martin