lisati

Apologies for the delay in replying. As helpful as the "X-Originating-IP" address can be in gathering clues to an email's apparent source, they can be forged. What some providers do is an analysis of the content of the email, sometimes the headers only, sometimes the complete email. Depending on the results of the analysis, the options open to the provider include (1) rejecting the email outright (works best when done BEFORE the complete email has been accepted for delivery), (2) flag the email as spam (possibly by altering the subject), (3) flicking the mail into a spam or Junk folder, or (4) accept the email unchallenged. Be extremely wary of solutions based on some kind of challenge-response system. Because the sender address can easily be forged, it's very easy to annoy innocent third parties

The only Received header that you can trust with any degree of certainty is one inserted by a server you administer, preferably the server that drops the incoming email into the recipient's inbox.

Thanks for the heads-up. The copy I have on my machine seems to have auto-updated to 1.21.0, and I didn't even notice......

@Bernhard: I'm not sure why your server is blocking based on the mailspike "rep" (reputation) list. I had a look at their web page, and get the impression that it's not a general purpose list suitable for blocking everything from a listed IP address. Mailspike's "bl" and "z" lists seem better suited to blocking/rejecting unwanted incoming emails.

Have a look here: https://www.spamcop.net/fom-serve/cache/329.html#bounces

I wish to disavow any connection with the above response.

What? Did I blink and miss something by not visiting this forum for a few days? Anyway, it must be time to consider a hot cuppa in anticipation of a speedy recovery......

A listing in the Spamcop list is based on users reporting unwanted email being provided to the people who run it. If you discover that your server is listed, you can use the Spamcop lookup page, which will usually offer some more information and suggestions. You can also find some information here: https://www.spamcop.net/bl.shtml?[IP]

I've had gmail refuse to forward reports on occasion. I haven't notice any useful pattern (yet).

One addon for Thunderbird I checked out a few months back was ThunderSec. If I remember correctly, it popped up a message similar to the "Thunderbird thinks this message is junk" message that appears when the email is flagged as junk. I don't think I figured out how to use it as part of a filtering scheme. Link: https://addons.mozilla.org/en-US/thunderbird/addon/thundersec/

Ah, I see what you did there. To add to what Petzl was saying, plugging in the IP address in a site which does rDNS checks, I see a possible problem, the rDNS comes back with a different domain name which in turns points to a different IP address. That could be what's tripping things up for osas.

Why do you think that your domain is listed on the Spamcop list? Spamcop lists IP address, not domain names. If you are referring to the listings on the RFC-CLUELESS listings, you will have to refer to their website.

True. When I was running my own email server a few years back, I had what amounted to private blacklists, hidden from public view until an incoming email ran foul of the filtering I had in place. I never got round to running a DNSBL/RBL.

If it's on abuseat's CBL list, it will usually find its way to spamhaus's ZEN list as well, I think Spamhaus took the list over a year or two back. I'm also seeing listings on other lists as well.

Just a thought: if Google, or any other provider for that matter, does something at their end that interferes with Spamcop's ability to correctly identify the source of an email, it's not necessarily Spamcop's fault. The team at Spamcop are under no obligation to jump to attention and make changes every time we, the users, encounter something that trips up the parsing and reporting process. They will have their priorities, which might not always coincide with what we'd like to see happen. There have been some good suggestions in this and similar discussions. I wish you all well.