Excessive Bounces

[Greg Stark]

Well with yahoo domain having a hard fail specified it looks like it's too
stay. The typical troublemaker with yahoo mail is lists modifying message
bodies or subject lines. Those practices will gauge have to end (and
frankly it can't be soon enough imho).

That said the usual consequence is that messages *from* yahoo through the
list get binned for Gmail users or anyone else who enforces DKIM. I've
noticed Gmail has started marking messages in Spam with the reason why
they're there and when they first started a *lot* if them were due to
signature fails. There are very few these days which make me believe the
lists I'm on have changed practices. Certainly yahoo hasn't rolled back
their dns records.

So unpredictability makes since sense as the bounces you see will be very
dependent on the domains *sending* the messages and their dns records. If
you have a thread with a couple yahoo uses talking back and forth you could
well see a series of bounces from users on servers that respect Yahoo's dns
records requesting a hard fail.

-- 
Greg