• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a pho

Shrewd marketers devote a great amount of attention to crafting their email messaging campaign.  They scrutinize the subject line, fuss over the content, and carefully monitor the timing of delivery.

Once the perfect message has been created, it is just as important to focus on its successful delivery to the intended recipients.  Unfortunately, it is likely that your current email address list has a number of significant problems.

Your List Has Inappropriate Addresses

The beauty of the Internet is that it connects you to everyone.  The danger is that there are people out there you would rather not be connected to.  Obviously, you want to keep these people, and their moments of malice, off your list.  Some common situations include:

1. Bogus Addresses

Some of your visitors will never disclose their email address to you.  If an entry is required, they will make something up.  A frequent occurrence is some variation of "asdf@asdf.com", which happens when the user hits random keys.

2. Prank Addresses

An innocent person may be getting added to new lists daily, simply because they made enemies with the wrong person.  Sometimes the abuse is a prank subscription from one friend to another; other times it targets a public figure (e.g. billg@microsoft.com).

3. Malicious Addresses

Another common type of abuse is when someone targets your company.  Without you noticing, your email message is directed to someone who will make your life miserable.  This might be an email address to report spam (e.g.

Your List Has Old Addresses

Unfortunately, people change their email addresses all the time - when they switch jobs, move, switch Internet service providers, or enter or graduate from school.  Technical advances such as cable modems, as well as ISP pricing competition, mergers and failures continue to encourage this movement.

In addition to their ISP-provided email address, users acquire additional email addresses from their jobs or schools, hundreds of free web-based email services (e.g. Hotmail, Yahoo, etc.), and even pagers and cell phones.  According to IDC, registrations for webmail accounts are growing at 91% annually, and now exceed 100 million addresses.

Email address changes are also fueled by the growth in unsolicited email, as users switch email accounts to escape "spam". Services such as AOL allow users to create and manage separate screen names and associated email addresses, which may be used and abandoned at will.

As individuals change addresses and maintain multiple working email addresses for multiple purposes, it is unlikely that they will make a point of updating you.  Recent studies indicate that nearly 35% of Internet users change their email addresses each year, and this does not account for the multiple working email addresses being added every day.

Ideally, you are aware of this problem, and monitoring the percentage of your database that is bouncing.  Every bouncing address is an unread message.  After repeated testing, you may determine that some addresses are truly "dead" (rather than being a short-term bounce) and be tempted to remove these from your list.

It is equally important to pay attention to a much harder statistic to track - what percentage of your database are old addresses that aren't bouncing?  These are messages that are ending up in abandoned or throwaway Hotmail accounts, unread school accounts, ignored AOL screen names, etc.  Messages sent to old addresses will remain unread no matter how much you tweak your text, change your subject line, etc.  Or worse, the email account has been recycled, and you are actually reaching the wrong person.

Your List Has Typos

No list is immune from the introduction of typos.  These errors tend to be introduced through three different mechanisms:

1. User Caused

If you accept email addresses from your website, you probably experience a 1-8% typo rate (or more!), depending on the stringency of your email address validation routines and the carelessness of your visitors. Typical mistakes include:

• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a phon

2. Prank Addresses

An innocent person may be getting added to new lists daily, simply because they made enemies with the wrong person.  Sometimes the abuse is a prank subscription from one friend to another; other times it targets a public figure (e.g. billg@microsoft.com).

3. Malicious Addresses

Another common type of abuse is when someone targets your company.  Without you noticing, your email message is directed to someone who will make your life miserable.  This might be an email address to report spam (e.g.

Your List Has Old Addresses

Unfortunately, people change their email addresses all the time - when they switch jobs, move, switch Internet service providers, or enter or graduate from school.  Technical advances such as cable modems, as well as ISP pricing competition, mergers and failures continue to encourage this movement.

In addition to their ISP-provided email address, users acquire additional email addresses from their jobs or schools, hundreds of free web-based email services (e.g. Hotmail, Yahoo, etc.), and even pagers and cell phones.  According to IDC, registrations for webmail accounts are growing at 91% annually, and now exceed 100 million addresses.

Email address changes are also fueled by the growth in unsolicited email, as users switch email accounts to escape "spam". Services such as AOL allow users to create and manage separate screen names and associated email addresses, which may be used and abandoned at will.

As individuals change addresses and maintain multiple working email addresses for multiple purposes, it is unlikely that they will make a point of updating you.  Recent studies indicate that nearly 35% of Internet users change their email addresses each year, and this does not account for the multiple working email addresses being added every day.

Ideally, you are aware of this problem, and monitoring the percentage of your database that is bouncing.  Every bouncing address is an unread message.  After repeated testing, you may determine that some addresses are truly "dead" (rather than being a short-term bounce) and be tempted to remove these from your list.

It is equally important to pay attention to a much harder statistic to track - what percentage of your database are old addresses that aren't bouncing?  These are messages that are ending up in abandoned or throwaway Hotmail accounts, unread school accounts, ignored AOL screen names, etc.  Messages sent to old addresses will remain unread no matter how much you tweak your text, change your subject line, etc.  Or worse, the email account has been recycled, and you are actually reaching the wrong person.

Your List Has Typos

No list is immune from the introduction of typos.  These errors tend to be introduced through three different mechanisms:

1. User Caused

If you accept email addresses from your website, you probably experience a 1-8% typo rate (or more!), depending on the stringency of your email address validation routines and the carelessness of your visitors. Typical mistakes include:

• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a pho

In addition to their ISP-provided email address, users acquire additional email addresses from their jobs or schools, hundreds of free web-based email services (e.g. Hotmail, Yahoo, etc.), and even pagers and cell phones.  According to IDC, registrations for webmail accounts are growing at 91% annually, and now exceed 100 million addresses.

Email address changes are also fueled by the growth in unsolicited email, as users switch email accounts to escape "spam". Services such as AOL allow users to create and manage separate screen names and associated email addresses, which may be used and abandoned at will.

As individuals change addresses and maintain multiple working email addresses for multiple purposes, it is unlikely that they will make a point of updating you.  Recent studies indicate that nearly 35% of Internet users change their email addresses each year, and this does not account for the multiple working email addresses being added every day.

Ideally, you are aware of this problem, and monitoring the percentage of your database that is bouncing.  Every bouncing address is an unread message.  After repeated testing, you may determine that some addresses are truly "dead" (rather than being a short-term bounce) and be tempted to remove these from your list.

It is equally important to pay attention to a much harder statistic to track - what percentage of your database are old addresses that aren't bouncing?  These are messages that are ending up in abandoned or throwaway Hotmail accounts, unread school accounts, ignored AOL screen names, etc.  Messages sent to old addresses will remain unread no matter how much you tweak your text, change your subject line, etc.  Or worse, the email account has been recycled, and you are actually reaching the wrong person.

Your List Has Typos

No list is immune from the introduction of typos.  These errors tend to be introduced through three different mechanisms:

1. User Caused

If you accept email addresses from your website, you probably experience a 1-8% typo rate (or more!), depending on the stringency of your email address validation routines and the carelessness of your visitors. Typical mistakes include:

• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a pho

It is equally important to pay attention to a much harder statistic to track - what percentage of your database are old addresses that aren't bouncing?  These are messages that are ending up in abandoned or throwaway Hotmail accounts, unread school accounts, ignored AOL screen names, etc.  Messages sent to old addresses will remain unread no matter how much you tweak your text, change your subject line, etc.  Or worse, the email account has been recycled, and you are actually reaching the wrong person.

Your List Has Typos

No list is immune from the introduction of typos.  These errors tend to be introduced through three different mechanisms:

1. User Caused

If you accept email addresses from your website, you probably experience a 1-8% typo rate (or more!), depending on the stringency of your email address validation routines and the carelessness of your visitors. Typical mistakes include:

• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a pho

• joesmith@aol - missing the ".com"
• joesmith@aol.c - input box too small, user stopped typing
• joesmith@aol..com - double periods, sticky keyboard
• joe smith @ aol.com - extra spaces
• joesmith@aol.com" - invalid quotes
• joesmith@aol.cmo - transposition error
• joesmith@hotmial.com - likely misspelling of hotmail

2. Internal Entry

Many companies collect email addresses through phone centers, mailings, inquiry cards, etc.  The data entry of these addresses is another common source for typos, as often the validation routines are much less stringent internally than on your website.  In addition to the challenges of reading and interpreting handwriting, auditory misunderstandings can enter your database.  One of our favorite typos, entered by a phone customer service agent, is "joesmith@yahoodotcom".

3. Data Manipulation & Corruption

Regardless of how careful your company may be to validate or double opt-in every email address, the list is still vulnerable to errors in ongoing database management.  For example, on several occasions we have seen a forced truncation of records, which results in the last few characters of long email addresses being dropped.  Other times, a well-meaning database manager will design a quick (but insufficiently targeted) query to clean up or correct a typo they have seen in the data.  Unless the error is dramatic, faulty data manipulation or data corruption may remain unnoticed in a list for many months.

Your List Has Duplicates

Duplicate email addresses can result in disgruntled customers and database management challenges for your company.  Obviously, it is unprofessional to email your customer multiple copies of the same message.  Even though many duplicate addresses are the result of double entries by your customers, these very same people often become so irritated by receiving multiple messages that they unsubscribe from your list altogether.

These "obvious" duplicates are easy to catch and most database managers can quickly do a scan of your list.  Ironically, not all companies catch these duplicates, especially if they maintain several lists and forget to de-dupe between them.

The more difficult duplicates to detect are multiple unique email addresses owned and read by the same person.  Imagine if your customer initially gave you their Hotmail address, and then later gave you their AOL email address.  You need access to a sophisticated and comprehensive database of email addresses to discover these duplicates and to decide which is the customer's current preferred email address.

So Now What?

Now that you know your list has inappropriate addresses, old addresses, typos, and duplicates, what can you do?  There are a number of solutions, including:

Improve your email address validation routines
Worth looking at, but is this really your area of expertise?

Switch to double opt-in
Has pros and cons; won't solve all your problems

Manually review all email addresses for accuracy and appropriateness
Requires substantial effort by your staff

Start building your own block list and use the DMA's e-MPS (and other) suppression lists
Smart idea

Consider sending a standalone message confirming your customer's current preferred email address and requesting any updates
Are you willing to devote an entire message to this?

Maintain a list of your customer's alternate contact methods so you can be sure to reach them
Making telephone calls and sending letters to get updated email addresses will be costly

Remove every typo and bouncing email address from your list
NO!

Did you forget your customer acquisition cost?  How about the projected revenue a typical customer brings in each year?  Each lost customer is costing your company from $10 to $50 or more.  Removing an email address from your list simply because it is undeliverable is throwing your marketing investment away!

Welcome to NCOA for Email

You may already be familiar with NCOA for your postal addresses, a service that corrects and updates your snail-mail list.  What you may not have known is that since 2000, this service has also been available to freshen your email address lists. 

A typical NCOA for Email service includes the following functions:

Identification of addresses that should be removed from your list.  These may be addresses that match a list of suspicious addresses (e.g. abuse@aol.com", "none@none.com", etc.), match a block list, are unrecoverable bounces, or are duplicates.  Some services can also catch different addr