March 26, 2003
How To

Email List Hygiene 101 - How to Clean Your List, Plus 7 Ways to Stop Names From Going Bad

SUMMARY: Building a permission email list is incredibly frustrating these
days because up to 50% of new names go bad within 120 days.
Sometimes it feels like you lose names as quickly as you are
adding them! Now learn:

a. The 3 specific ways names go bad

b. 7 preventative measures you can take now

c. Quick notes on vendors who clean lists

A must-read for everyone who has an email list.
When you review your latest house list counts, do you ever feel
like you have been kicked in the teeth?

You are working harder than ever before to convince people to join
your email list. People are tired of email overload and wary of
spam. You know if you can just get them to join each
house list name is so much more valuable than any rental file you
could ever test.

Names are going bad at a faster rate than ever before. For
every 1000 names you torturously gather, you can lose up to 50%
within 120 days. (Number based on Sherpa internal research.)

The problem is not opt-outs. (The vast majority of consumers
do not bother to leave a list, they just click delete.)

The problem is email names going bad.

According to list hygiene services provider TowerData,
approximately, 20% of the addresses on lists it cleans are dead
as doornails. (These are lists owned by responsible mailers
who have been removing really bad bounces on a regular basis

-> a. The 3 specific ways names go bad

Bad names and bounced names are not necessarily synonymous.

Depending on who you talk to, there are 30-100 different things
that can cause an email to bounce. Often these problems are more
to do with technology than the actual end-recipient not being
there anymore. Servers go down, list senders are blocked,
mailboxes are temporarily full, people go on vacation, etc.

Which is why you never should cut a name off your list just
because it bounced a few times. On the other hand, if you have
too many bad addresses you are running the risk of being blocked
as an email sender.

For example, both AOL and Yahoo have been known to block senders
which consistently send mail to bad names.

The 3 main causes of bad names are:

#1. Typos or formatting problems in email addresses.

According to TowerData, approximately 2% of undeliverable names
are due to the name having been entered incorrectly in the first
place by consumers or data entry operators, or that have been
corrupted somehow in your database.

(Note: according to our own research, if your data entry
operators are working from handwritten email addresses, this
percent can be astronomically higher.)

TowerData gave us these examples of common mistakes:

Bad email --- Corrected version
john-doe#hotma.lcom ---
email me at ( ---
"Smith, Bessie" --- or ---
angie (a) --- --- ---
aaron@prodigy ---
mihaela@domain.corp --- --- ---
alan@classic,msn//com ---
jeff@o'neill.comcom ---
jane; ---
íÑßà ---
http// --- ---

(Please note: do *not* email any of the corrected addresses
above. We do *not* have permission to use them in any way aside
from posting them here for your education.)

#2. Dead domains

According to TowerData, about 15% of bad addresses on a typical
list are caused by dead or invalid domains.

Those pesky sites that go under or stop offering no-cost email
(@home,, iVillage) can wreak havoc with your list.

The addresses do not even bounce back, they just disappear. offers a neat list of upcoming and past major
changes in the free email industry. Check it out at

For more on no-cost email accounts going under and what you need
to know, check out this recent MarketingSherpa article, “Email List
Owner Alert: Top 7 Preventative Measures to Stop Up to 70% of
Your List From Going Bad,” at

#3. Address Changes

According to list hygiene provider Return Path, at least 30-35%
of consumers change their primary email address per year often
because they change jobs, switch ISPs, or bail on old addresses
to avoid email overload.

In fact, TowerData's found that a whopping 83% of bad names on a
typical list are due to address changes.

-> b. 7 preventative measures you can take now

Prevent your list from going bad as quickly as it has been by
taking at least a few of these basic steps:

#1. Ask customers to enter their email twice.

The experts we interviewed agreed that this helps and does not
discourage customers or send them running off to other sites.

“This request can significantly reduce user errors, and is
generally viewed positively by consumers, who understand you are
taking steps to ensure data quality,” Blumberg says.

Adding a short, polite note on your site explaining why you are
asking does not hurt either.

#2. Review offline data entry procedures

Call center service reps are notorious for typing in email
addresses they hear over the phone incorrectly.

“Provide your data entry staff with a list of common top-level
domains (.com, .net, etc.), domains (hotmail, yahoo, etc.) and
standard email address formatting rules,” says Bill Kaplan, CEO
Fresh Address.

“If you do any significant off-line data entry, investigate
implementing aggressive validation at the time of entry.”

#3. Ask registered visitors to correct their addresses

If your customers use a login, allow the IDs to flag addresses
that have gone bad. Then prompt them to update their email
address via a pop up window, Return Path's CEO Matt Blumberg

(We love this idea! You should extend it to names that have not
opened emails in a long time too, even if the account is not
bouncing yet.)

#4. Review your email broadcast firm's performance

It is not always your lists' fault. Review your bounces by domain
to see if your email broadcast provider may be blacklisted.

For example, TowerData's President Tom Burke says that last week
he was given a list of addresses to clean. When the
client used it, it did not work. As it turned out, the service
provider sending the emails was blocked by Juno. “It looked like
the addresses were dead, but they were valid customers.”

#5. Make address recovery easier, from the beginning

“Consider collecting a name, an alternate email address, a postal
address, or a phone number,” Kaplan says. This info can help you
track down a new email address when the old one goes bad.

Asking for more data will lower the number of sign-ups for your
newsletter. The more fields someone has to fill out, the lower
the rate. Unless you are gathering the data another way
(such as through a shopping cart), consider making the additional
questions non-required page-two of your sign-up form. That way
you still get the email address even if prospects do not feel like
typing any more.

#6. Validate new addresses at sign-up

Validate at the sign-up point. “When the customer clicks
‘confirm’ have validation systems check the email,” Burke says.
“It could be a java script or a higher end product. If the email
tested is not a valid address, send a message, ‘That domain is
not valid. Please enter another email address.’”

(Actually, we recommend wording that in more user-friendly
language that matches your brand, unless your users are

#7. Move to Double Opt-In or email fulfillment

To make sure the address given belongs to the person signing up,
and it is an active address in an email box they are more likely to
check frequently, move to double opt-in whereby names are
required to respond to a confirmation email prior to being added
to your list.

To improve your conversion rate on the email RSVP, offer
something sexy that the prospect will definitely want to get
their hands on right away when they click through the email.
Perhaps it is password access to a section of your site, a special
report, results from a quiz they just took, use your

An added benefit of going double is that you are able to deal
with potential spam-complaints (and there are always a few no
matter what) much more easily.

-> c. Quick notes on vendors who clean lists

You should also invest in getting your list professionally
cleaned on a regular basis.

At the very least, peel off your multiple-bounces into a special
file and send it to the cleaners every 120 days. (If you wait
too long after that, people will forget they were on your list
and may view renewed communications with suspicion.)

Return Path says that 75% of their clients run the services on a
regular basis, at least quarterly, the other 25% run the services
on an adhoc basis

We chatted with three of the leading vendors to get some quick
info for you. There are other vendors out there who may be great
too, this is not an endorsement of anyone in particular, just a
starting point.

List cleaning can encompass four factors:

1. Running your file through a list hygiene system to catch
general syntax errors, invalid characters, invalid domain syntax,
invalid username syntax, missing usernames, missing or multiple @
signs, etc. Some even try and fix the placement of periods.

2. Removing bogus email names ( and malicious names
( Your list cleaning service should have a whole
list of these they can show you on request.

3. Fixing domain names that have typos, and giving you a list of
names which are using domains that no longer exist so you can
contact those customers through another method to get a new email
if you wish.

4. Running your list through some type of address updating

However, be forewarned, unlike the NCOA (National Change of
Address System) maintained by the US Post Office, there is no one
single official email change system yet. The solutions available
are imperfect, but far better than nothing at all.

“I talk to a lot of companies that tell me they do list hygiene,”
Bill Kaplan, CEO FreshAddress says. “They tell me that if an
address bounces 2-3 times they get rid of it. I say, don’t throw
them away. A change of address doesn’t mean they don’t want to
hear from you.”

Since there is no single official USPS email address forwarding
system (yet), the way that different services collect, append and
sell revised names to you can differ widely. The option you pick
not only affects price, but also can raise serious privacy

- Some services email the user first to get specific new
permission before handing over the changed address to you.
People have to say "yes I want to be on that list." This is
the highest level of privacy, and should certainly be used
for prospects and lapsed customers lists, if not active

- Some services email the user first to offer the user the
chance to say no to you. People are on your list unless they
opt-out. This is a lower level of privacy. Depending on
your corporate privacy policy you may wish to use it for
active buyers, but it is not recommended for prospects or
lapsed buyers who may be offended.

- Some services simply append the email address without
checking with users to see if they have any opinion about
getting mail from you or not. We do not recommend this to a
privacy-sensitive company.

When choosing which option you will go with, realize that some
people may have changed their email address specifically to stop
getting so much email! They may be highly offended if your
messages follow them to their new in-box, even if in the past
they used your services or registered for your list.

It is a touchy area. Do your best, and good luck!

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