brain trust: email-routing question

[cellio]

Dear brain trust,

On my domain, I have email addresses that collect a local copy (i.e. I can use webmail on my domain to read them) and also forward a copy to my Gmail address. This is particularly helpful for low-volume addresses that I might not otherwise check frequently.

Today somebody with whom I'd been corresponding contacted me via another channel to report that his email was now being rejected -- by Gmail. Sure enough, the copies are sitting in my domain mailbox just fine, but there's no sign of them at Gmail -- not in trash, not in spam, just not there. Gmail seems to have decided to reject them and not even tell me.

I have questions.

1. How do I get Gmail to stop doing that, at all? If email is sent to my Gmail address, especially by my own forwarder!, I want it to show up there. In the spamtrap is fine if Google thinks it is. Silent deletion is Not Ok.

2. If I can't get Gmail to stop doing it, can I get notifications somewhere?

3. I expected the forwarding from my domain to Gmail to be a private matter between those two parties. Why did the Gmail rejection get all the way back to the sender? Why did I not receive a notice of the rejection at my domain address, which is what sent it along to Gmail? Is there something I can do, presumably via CPanel, to intercept rejections by forwarding addresses?

4. Gmail has filters, which can be used to process incoming email in various ways. I've used them to whitelist a few senders that Gmail thinks are spammers that aren't. When in the pipeline do filters get applied? I think it's after this rejection it's doing, since the message goes nowhere that I can see, but I've whitelisted this particular address now in any case.

Comments

[rhialto]

Do you have access to the log files from your outgoing mailer? It may well be that google's refusal isn't 100% quiet, but has some error message there. The one I got was fairly non-informative (I don't remember the exact text) and referred to a web page that basically almost accused me of being a spammer or other ne'er-do-well (and which had no help that applied to the situation).

I did however discover that google seems to be much more strict on its IPv6 connections than on IPv4. No idea why. One would think that the new way is more rarely used (and hence abused) than the old way. But the result was that if I forced my mailer to connect to google using IPv4 instead, my mail would arrive. If you happen to use Postfix I can show my config fragments for that (and maybe I can even remember how it works ;-)

That the original author receives the rejection and not you isn't so strange. From a mail system point of view, you're just a forwarder, and error messages make in general more sense if they go to the author than to some random handler in the middle. Think "this mailbox doesn't exist" type of errors...

[cellio]

Thanks. It occurred to me after posting that, as you say, Gmail can't tell it's via a forward and so it's logical to send the rejection to the original sender. That made me wonder if a forwarder can inject a "no, if there's a problem tell this address instead" header.

Good question about logs. I'm going to have to dig around to see what I have access to. I have what I understand to be fairly conventional hosting, with CPanel as the configuration front-end but I can ssh to my server (which I do sometimes to manage web content). I assume logs would be somewhere on that server.

[siderea]

Good question about logs. I'm going to have to dig around to see what I have access to. I have what I understand to be fairly conventional hosting, with CPanel as the configuration front-end but I can ssh to my server (which I do sometimes to manage web content). I assume logs would be somewhere on that server.

I do not believe CPanel conventionally logs outgoing mail. I wound up building my own logging system, for my unconventional forwarding system.

[siderea]

That made me wonder if a forwarder can inject a "no, if there's a problem tell this address instead" header.

Okay, I've gone and looked this up and: I think so. Just not cpanel's ordinary forwarders, which can't do anything interesting with email header re-writes. My system definitely can, and now that I think about it, maybe it should! Hmmm. I am going to have to go think about this.