{"id":32312,"date":"2014-05-06T06:30:12","date_gmt":"2014-05-06T06:30:12","guid":{"rendered":"https:\/\/wp.lvh.me\/blog\/2014\/05\/06\/checklist-7-key-points-to-check-the-quality-of-a-database\/"},"modified":"2026-10-15T16:08:56","modified_gmt":"2026-10-15T16:08:56","slug":"checklist-7-key-points-to-check-the-quality-of-a-database","status":"publish","type":"post","link":"https:\/\/mailrelay.com\/en\/blog\/2014\/05\/06\/checklist-7-key-points-to-check-the-quality-of-a-database\/","title":{"rendered":"7 key points to check the quality of a database"},"content":{"rendered":"\n

We’ve always advised you to build your own subscriber database.<\/p>\n\n

Ideally using the double opt-in method<\/strong>, as it’s more effective at building quality databases.<\/p>\n\n

But sometimes that isn’t possible, it doesn’t suit you, or you simply need to launch your bulk email campaign as soon as possible.<\/p>\n\n

For whatever reason, you’d rather buy your database, legitimately generated<\/strong>, from a provider.<\/p>\n\n\n

How do you know whether the database you’re buying is a quality one?<\/h2>\n\n

It’s not a trivial matter: both the success of your email campaign and your domain’s reputation depend on it.<\/p>\n\n

You’re not the only one with these concerns.<\/strong><\/p>\n\n

Many customers have asked us how to analyze the quality of a database and spot potential problems in it.<\/p>\n\n

The key points you should check before launching your bulk email are:<\/strong><\/p>\n\n

1)<\/strong> Check for duplicates and syntax errors in the email addresses2)<\/strong> Check the number of bounces3)<\/strong> Look for suspicious or problematic email addresses4)<\/strong> Check whether it contains addresses that have filed spam complaints or unsubscribed5)<\/strong> Make sure it’s an active database6)<\/strong> Check whether the addresses are public and ask for the sign-up logs7)<\/strong> Run a pilot test and check the results<\/p>\n\n

Let’s go through these points in detail.<\/p>\n\n

First of all, we’ll start from the assumption that we have a legitimate database<\/strong> purchased from a co-registration provider, an industry portal, through agreements with companies<\/a>, etc.<\/p>\n\n

The subscribers in this database have given their informed consent<\/strong> to receive promotional emails, bulk emails and other promotions.<\/p>\n\n

They are aware that their data has been transferred for this purpose.<\/p>\n\n

As I said, we’ll start from this assumption, so when you buy a subscriber database, above all:<\/p>\n\n

“Make sure the data has been collected in accordance with the law and that the subscribers have been properly informed”<\/strong><\/p>\n\n

Otherwise, your bulk email campaign will fail before it even starts.<\/p>\n\n

Let’s continue.<\/p>\n\n

Assessing the quality of the purchased database<\/h2>\n\n

There are several potential problems in a database that can ruin our email marketing strategy.<\/p>\n\n

These include spam traps, old lists full of bounces, spam complaints, etc.<\/p>\n\n

Let’s see how to detect them using the features of Mail<\/span>relay<\/span><\/strong>.<\/p>\n\n

1) Check for duplicates and syntax errors in the email addresses<\/strong><\/h3>\n\n

The most basic requirement for an up-to-date, properly maintained subscriber database is that it has no duplicates or invalid email addresses<\/strong> with syntax errors.<\/p>\n\n

For example: inf\u00f3@mydomain.com, sales@@,mydomain.com, myemail@gamil.com and the like.<\/p>\n\n

If a quick review shows it has them, we should ask for an explanation: if they didn’t take care of something so basic, we can hardly expect them to have been more careful with more advanced matters.<\/p>\n\n

When you import your database into Mail<\/span>relay<\/span><\/strong>, many of these errors are detected automatically<\/strong>:<\/p>\n\n

\"Result<\/figure>\n\n

<\/p>\n\n

If you see a lot of errors in the import, be wary of the database’s quality.<\/p>\n\n

2) Check the number of bounces<\/strong><\/h3>\n\n

A quality database should be up to date and well maintained, so it shouldn’t contain bounced or failed email addresses.<\/p>\n\n

To check this, we can upload it to Mail<\/span>relay<\/span><\/strong> and see how many bounces it has in the subscribers section (more information in “How Mail<\/span>relay<\/span><\/strong> handles bounces”):<\/p>\n\n

\"List<\/figure>\n\n

<\/p>\n\n

If the database really is good and up to date, bounces should never exceed 5%<\/strong>.<\/p>\n\n

Otherwise, it’s probably old and can therefore cause problems, even with the valid addresses, since people may not remember where they signed up and may file spam complaints.<\/p>\n\n

Excessively high bounce rates are harmful to your sender reputation<\/a>.<\/p>\n\n

There’s no point in buying a database to send a bulk email if it won’t reach anyone because the accounts are invalid, incorrect or haven’t been used for a long time.<\/p>\n\n

3) Look for suspicious or problematic email addresses<\/strong><\/h3>\n\n

You’ll have to do this manually.<\/p>\n\n

We need to look for suspicious addresses such as<\/strong> junk@gmail.com, allspam@hotmail.com, billgates@microsoft.com, etc., which can be a clear sign that the people who signed up entered fake details or accounts they have no intention of actually using.<\/p>\n\n

This happens often when the data has been collected at trade shows, events, giveaways and the like, where users entered their details manually.<\/p>\n\n

Whether on purpose or by mistake, we can come across this kind of email address.<\/p>\n\n

And if we find some, we should ask the provider to account for them, since they should have cleaned the database beforehand.<\/p>\n\n

4) Check whether it contains addresses that have filed spam complaints or unsubscribed<\/strong><\/h3>\n\n

To do this, we’ll need to cross-check it against our account’s list of unsubscribes and spam complaints and see if there are any matches:<\/p>\n\n

\"List<\/figure>\n\n

<\/p>\n\n

You can also contact the Customer Support team<\/a> at Mail<\/span>relay<\/span><\/strong> for a more extensive analysis with empirical data from our platform.<\/p>\n\n

But in the first instance, if the database has spam complaints, we should question its quality.<\/p>\n\n

5) Make sure it’s an active database<\/strong><\/h3>\n\n

We should ask the provider for an activity report on that database covering the last 3 months.<\/p>\n\n

In other words, if it really is good, it should have a good percentage of recent opens and clicks<\/strong> confirmed in their system.<\/p>\n\n

This point is related to the one about bounces.<\/p>\n\n

An active database should have fewer bounces, since bounced emails “should<\/strong>” be cleaned out as the list is used.<\/p>\n\n

Sending a bulk email to a database that has been inactive for a while can sink our sender reputation.<\/p>\n\n

6) Check whether the addresses are public and ask for the sign-up logs<\/strong><\/h3>\n\n

Another thing you can check manually.<\/p>\n\n

We can pick a few addresses at random and search for them in quotes on Google to see if they appear on websites.<\/p>\n\n

If all or most of them do<\/strong>, it’s very likely the database was built from public lists rather than from active sign-ups.<\/p>\n\n

It doesn’t hurt to pick several random email addresses and ask the provider for the sign-up and confirmation logs, with the source IPs, time and date.<\/p>\n\n

7) Run a pilot test and check the results<\/strong><\/h3>\n\n

Finally, before sending to the whole database, it’s a good idea to run a pilot with a random 10%<\/strong>.<\/p>\n\n

This lets you see the results, or even contact some subscribers at random so they can confirm that they signed up and that their details are genuine.<\/p>\n\n

Related posts:<\/p>\n\n