Re: DMARC

> I've been using majordomo2 on my server for years, but I confess I don't 
> understand mail protocols and policies very well. I'm wondering what you all 
> think is the best way to change my list settings so Yahoo subscribers will 
> get mail.

Actually, that's not the problem -- subscribers at any ISP that does 
DMARC, which includes AOL, Yahoo, Hotmail, Gmail, and Comcast, among 
others, won't see mail from AOL or Yahoo subscribers.  Depending on how 
they implement DMARC, those lost messages might bounce, thereby causing 
innocent bystanders at other ISPs to be bounced off your lists.

I added an output shim that rewrites AOL and Yahoo From: addresses by 
adding the reserved name .INVALID, e.g.

   From: Marissa <[email protected]>

turns into:

   From: Marissa <[email protected]>

That works great, no DMARC bounces, and it's a hint to Yahoo users that 
they might want to find a better mail provider.  Unlike Yahoo's purported 
"solutions" it doesn't screw up the From: line for everyone else.

You're welcome to my shim, but it's fairly specific to the qmail back end. 
I wouldn't think it would be hard to patch MJ::Deliver::Envelope to have 
the send() routine do the same thing.

Regards,
John Levine, [email protected], Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. http://jl.ly