The worst is when they accept the mail but silently tag it spam and put it some place the intended receipient will never see it. Google's gmail is the worst about this. Corporate email isn't email anymore. It's a walled garden / silo like Facebook.
Thank god.
Otherwise I'd drown in cold email spam.
edit: But on a serious note — I'm using Gmail for all companies because I gave up trying to run and administer our own server. It's a travesty that this has become so hard. I feel if you're not on a well-configured Gmail Workspace there's no chance your email gets through, even if legit.
i would love some insights in how smart spammers are in actually leveraging such information. most spam seems to be hammering attempts that don't take failure feedback into account.
in my mail server, messages classified as junk keep getting temporarily rejected with a generic error message. at least the (legitimate misclassified) sender gets a delayed dsn, and finally feedback that a message wasn't received.
it seems many mail servers/services think it's more important to not give a signal to spammers than it is to give a useful signal to legitimate but misclassified users. perhaps they think their classification is really great and doesn't misclassify...
Gmail's spam filter (and promotions filter) works with >99% reliability as a user, with really trivial numbers of false positives.
Customer requests for quotes, Paypal/Stripe security messages, lots of other important emails go to spam.
See e.g. https://github.com/nh2/gmail-spamfilters-paypal-security-mes...
For a while now I suspect that GMail has some bug with its own group email addresses:
When somebody sends an email to our GMail group email address team@example.com, it shows up in GMail as "Sombody via team@example.com". Of course, teamexample.com receives both spam and non-spam.
I suspect that when we mark spam that comes "via team@example.com", GMail learns that as "things 'via team@example.com' are often Spam", even though info@example.com is a Google Groups email.
And by now, everything that comes 'via team@example.com' is marked as Spam.
So it seems that when we mark an email that arrived at team@example.com as Spam, Google punishes its own Group email address, instead of the sender.
It's Google's own group of my own org. Does it make sense that the spam button would punish my group own email?
Also, if I mark it spam in the Groups interface, it's still polluting the inboxes of all my team members where it has already arrived, right?
I'd have to tell my team to never use the spam button on obviously spam emails. That doesn't make sense for a business email product!
at this point maybe you should just create a filter rule
If it wasnt walled, it would be completely unusable.
The ability to know an address is the only license you need to send to it. The only reason you haven't had a bad time with this is because you haven't been a target.
It sounds like stiffer penalties are necessary for sending spam, both to consumers and to businesses.