[jandrese]

It's not just small fries getting hit by this. Google regularly refuses to deliver mail from backerkit.com to my account, by far the most popular Kickstarter fulfillment support service. I frequently have to contact Kickstarters and ask them to manually send me mail because Google is refusing to accept it, which is annoying and wastes their time.

I wish Google had a way you could tell it "messages from these people/domains are never spam (or I'll deal with it myself)".

[Xamayon]

Google Apps (or whatever it's called now after the last dozen name and service changes since "Postini") does offer a whitelist function, but as far as I can tell it's there only to placate users. Whitelisting domains or individual email addresses globally, or per user seems to have no bearing at all on whether they will show up in your inbox... Postini used to work flawlessly, it's hard to imagine how they could have screwed it up so badly.

[acomjean]

It’s AI above all else. It seems instead of a rule that says all emails from these people are ok, they’re too reliant on ai filtering based on the content. They’re probably trying to prevent spoofing.

I use gmail and they know who is sending. I got an email today with a gmail flag saying “this user sent from a different email address previously”

[sbov]

In gmail, you can create a filter to skip the spam folder. I regularly receive emails where, at the top it says "this would have gone to spam, but you told us not to send it there".

I doubt this affects things when messages are rejected at the protocol level, but if your problem is emails showing up in the spam folder, this might fix it.

[necovek]

One of the problems is the pure mechanics of how SMTP works: anyone can send an email with any "from" address, and filtering on people/domains in the "from" field is basically pointless if you want to catch spam.

What Google is likely doing is checking the domain of the originating IP in the SMTP "envelope", but that also gets tricky with outsourced email services or internal IPs.

I do not use Gmail, so these are just wild guesses, but I do run my own mail server and frequently get my email not showing up for people.

Problem with SMTP bounces is that it may take a week for the final bounce to show up in my inbox (because again, that's how SMTP protocol is designed, to expect nodes to be down and retry a number of times).

[wtfrmyinitials]

> anyone can send an email with any "from" address, and filtering on people/domains in the "from" field is basically pointless if you want to catch spam.

Isn’t this the exact thing that DKIM is designed to fix?

[necovek]

This was a response to a complaint about not receiving emails from some "people/domains" even when whitelisted, and I highlighted how this can be hard for a service to detect reliably.

So yes, DKIM will help a receiving server know for sure, but a receiving server still needs to accept emails from non-DKIM-enabled servers, and perhaps that's why whitelisting didn't work for the parent.

[Neil44]

Bounce handling depends on the error code, 5xx is usually a permanent error so the bounce is immediate. Mailbox doesn't exist etc. Its not going to exist later either. IIRC 4xx is effectively try again later because something is wrong right now that might get fixed. Mail server out of disk space, you're greylisted etc. So try again later. Those can take a few days to give up retrying.