Yahoo's Quirky Bounce Codes & Whitelisting

Into the bulk mail folder! That's where we found that our
newsletters were being filtered by Yahoo for those Yahoo
recipients who had filtering enabled.

We looked at the content, and ran some tests, and we couldn't see
any correlation between our content and filtering.

We had the scoop on getting whitelisted at Yahoo, so we sent off
an inquiry to mail-abuse-bulk@yahoo-inc.com, requesting
whitelisting. We gave them a bit of reassuring detail about our
lists and our newsletters. Within 24 hours we had a reply from
their mail-abuse desk. The reply included a text form for us to
complete.

After submitting our answers to their 14 questions, we got an
answer in less than 48 hours that we had been approved for
whitelisting.

The only problem we had was with Yahoo bounce codes.

When your email server sends a message to a subscriber's email
server, if the subscriber can't receive the message for any
reason, you get back a bounce code. There are rules about how the
subscriber's mail server is supposed to assign bounce codes. If
you've heard about "hard" vs. "soft" bounces, then you have some
idea what I'm getting at here.

Bounce codes - there are so many of them that Lynda Partner of
GotMarketing told me just this morning that she had 38
classifications of bounces in her system! - are supposed to be
assigned objectively. However, sometimes email administrators
take liberties with error codes. What this means is that a
"temporarily over quota" (which should be a "soft bounce")
condition can return a "permanently undeliverable" (hard) bounce
code that actually instructs your list host software to delete
that address.

Yahoo has been returning "554" codes, which means "Go away. Stop
trying to reach this address. It is not valid. It will never be
valid." That is the kind of hard bounce message that should cause
you to delete that address from your list.

There is a legitimate use for a "554." If an employee leaves a
company, then the mail server should give you a 554, but with
Yahoo and quotas, every "permanently undeliverable" is not
necessarily so.

Of course, mailers know that. We know that. We had been reluctant
to purge all our Yahoo 554s because we knew that some of them
were really just temporarily over quota. Of course, if we had
more sophisticated email software, we could probably have told
the system: "Delete a Yahoo 554 only after 4 weeks of seeing this
error." That would delete the address only if they were over
quota for 4 weeks, which probably means it is a throw-away
account, anyway.

In order to get/keep our Yahoo whitelisting we had to deal with
these addresses. We pretty much concluded that our bulk listing
was their way of telling us, "Clean your list and respect our 554
errors."

So . . . we decided to delete all the addresses that returned
Yahoo 554 errors from the previous week, thinking that if we did
this (manually), on a monthly basis, no address that was
returning 554 errors would do so for more than a month.

Then, of course, we heard from the readers who had been
unsubscribed against their will - confirming our theory that
these weren't really bad addresses after all.

We are going to continue to keep our Yahoo addresses clean - even
though we know their "permanently undeliverable" message isn't
entirely true. We don't want to risk our whitelisting.

Should you do the same? I suppose it depends on how many
addresses you're talking about. Ideally, your broadcast email
software would allow you to specify that an address that receives
a "permanently undeliverable" (hard bounce) message only gets
deleted after a certain number (or interval) of consecutive hard
bounces. Even then, however, increasingly aggressive email admins
might be giving you the wrong message through their bounce codes
- and there's really nothing you can do about it.