On Sat, 2018-03-31 at 17:57 -0400, Richard Damon wrote:
On 3/31/18 3:35 PM, Lindsay Haisley wrote:
On Sat, 2018-03-31 at 14:50 -0400, Richard Damon wrote:
To me the issue sounds like why is fmp.com forwarding spam?
If this is a case of fmp.com offering forwarding mailboxes to users, who might be using gmail as a final destination, then yes, fmp needs to try to be as good at detecting spam as gmail or users need to accept the increased spam levels.
If pigs could fly ....! I do the very best job I can of filtering spam from inbound email, and get about 90% of it, maybe more, but fighting spam is a forever job of whack-a-mole. I certainly wish that I could do as good a job of parsing spam from legit email as Gmail does, but I'm a one-person shop, and have many tasks. Gmail has dozens, perhaps hundreds of very smart people assigned to managing their spam filtering, and they do a very good job of it. I could _never_ hope to match their efficiency or accuracy, nor could most small operations such as FMP Computer Services.
But coming at least close is the job you sign up for in being a mail forwarder. You at least need to be good enough that you aren't seen by google as an uncaring domain, and maintain enough information that they can continue to do what they do well.
Rest assured, we "come at least close". This is not an option here, it's a necessity. Email redirection is a feature of my MTA (Courier) and has been offered since FMP went into business in the 1990s. It's a standard feature of many MTAs and many ESPs offer it.
I've had to deal with Gmail's honey-potting before, and I can do it again if necessary. I don't imagine that you've ever done commercial email administration, Richard, or you might have something constructive to say instead of just spewing admonitions to "do better".
The problem is that Gmail is whitelisting based on the From address, rather than the Reply-To address, which should be an _option_ open to users. On Google's scale of operation, I'm just a fly on a dog turd so any feature which might benefit my users and subscribers is pretty much a no-nevermind for them.
Which is why I was saying make a 1:1 mapping of From addresses to Reply-To addresses.
The From address _has_ to be from an address at fmp.com, which is the reason for From-munging in the first place. If you don't understand how DMARC works, or the problems it causes, Mark, or someone else on this list can send you to a reference on it. The Reply-To address is EITHER the original Reply-To address on the received email, or, if it had none, the ORIGINAL From address. Mapping the Reply-To address to the munged From address makes no sense at all.
Another option is to deterministically munge the from address so every incoming email address gets a unique fmp address that it represents (it doesn't have to be absolutely unique, mostly unique is likely good enough), something like replace the at with _at_ and add a tail wart like _dmarc@fmp.com (so you can have other addresses an not worry about possible overlaps with those) and use that as the from address. Then a reply will only whitelist that specific original from address. Which, as I noted in my original post, will cause the Gmail user's mail account to end up with a whole lot of useless whitelisted address which would need to be deleted, and FMP's server might well end up getting blacklisted as a result. No more than if GMail did implement a white-list on Reply-To addresses.
No, because the Reply-To address is the _original_ From address. Such a whitelisting would be useless as long as Gmail's policy with regard to DMARC rejection remains in place, but unless we get into some kind of meta-heading BS, it's the best we might do.
--
Lindsay Haisley | "The first casualty when
FMP Computer Services | war comes is truth."
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http://www.fmp.com | -- Hiram W Johnson