The number of emails in the database isn't even the interesting part. What's more noteworthy is the fact that the spammers have figured out how to evade Google and Yahoo SMTP servers' rate-limiting techniques, and the sheer amount of volume they have at their disposal relative to the compute resources they have.
That's interesting, I never get spam in my inbox in Gmail, but my "spam folder" is constantly full. I wonder if gmail makes these spam emails appear as if they're "inboxing" to the spammers.
At the SMTP level, you can't tell the difference (spam or not). A bounce return message will tell you it fails, but the absence of a bounce message doesn't mean it was received, let alone got into an inbox.
The only way a sender can tell for sure their e-mail was delivered is to have tracking links: images and/or clickable links that include something to uniquely identify which address received the mail.
Most if not all e-mail clients block images, and many even disable links for unknown senders and/or messages that even remotely look like spam (eg: a non-zero spam score that is below the threshold to automatically reject or filter to a junk folder).
If you get tracked by one of these images or links, presumably you move from the "maybe working" e-mail address list to the "reads our messages" or "clicks our links" list, and at the very least means you contribute to making more money for the spammer when they sell that (higher-value) list.
> The only way a sender can tell for sure their e-mail was delivered is to have tracking links
Thats not true. Both spammers and legitimate email delivery services have hundreds if not thousands of accounts at the major email providers that they seed into their lists. As they are delivering email they periodically check their own accounts to see if mail is ending up in the inbox or the spam folder.
You can also request a "Feedback Loop" from major email providers that will forward spam complaints from your network back to you.
I stand corrected. Must be a setting I changed at some point then, as I have it set to always ask.
It's a terrible setting, it should just be 'always ask'. Is there a legitimate use I'm missing? The only thing I can think of is for spammers to track if their spam went through, marketers of 'legit' mail to track the same thing, or a backdoor way to implement the atrocious 'read receipt' feature. None of those is at all beneficial to the user receiving the message.
