by richardh
2. February 2012 10:57
We have recently announced changes to our email validation services.
Accurately validating an email address is a notoriously difficult thing to do. The simplest approach is to ensure that the syntax of the email looks correct - for example, there is an @ sign and the domain ends in a known top level domain such as .com. However, this is a very simplistic approach and allows many invalid email addresses through.
A much more useful and accurate service would check to see if the email address is alive, available and accepting emails to be sent to it.
The data8 approach now has 4 possible levels to check an email address.
Consider the email address info@data-8.co.uk. This is broken into a domain part: "data-8.co.uk", and a local part: "info".
- Firstly is it syntactically correct? Are all the characters valid and it looks like an email address?
- Secondly, does the domain part refer to an internet address correctly configured to send email?
- Thirdly, is the mail server alive and responding to requests?
- Fourthly, does the mail server allow you to send emails to the local part?
Unfortunately, it is not always as simple as this. If it was, the most obvious side affect would be that email spammers would be able to generate lists of all valid email address by using trial and error. In practise, if you try to validate lots of emails in this way - and there are many software packages that you can buy that do just this - then you will quickly find yourself blacklisted and unable to send any email to anyone. Not a good situation.
Also, many email servers employ various methods to make all of this difficult. Two common tricks that we can detect here when performing our most detailed validation are:
- Catch-All - a mail server configured with a catch-all rule means that any email sent to any email address is accepted. It is either just deleted, forwarded to another email address, or rejected and bounced (a soft bounce) a few minutes later. The data8 solution now detects these mail servers so that you can distinguish between a genuine good email address and an email address that is held on a mail server with a catch-all rule.
- Grey-listing - some mail servers are configured with grey-listing techniques. This means that the mail server initially rejects any approach to send an email and says please try again later. The idea here is that spammer would tend to give up at this point and move onto the next email address. The data8 solution detects grey-listing techniques and returns a different return code.
By using a data8 cloud based solution, you are not putting yourself at risk of becoming blocked and barred for looking like an email spammer. Data8's experience of validating millions of email addresses and our relationships with the major ISPs means that our service will continue to work without risk of black listing. You can also be assured that we are giving the highest possible validation rates with the lowest false positive rate.
The data8 email validation service can be used in batch to cleanse a list of email addresses, or in real-time to validate whether the email address is correct at time of capture. Contact us to arrange for a free trial or a free data quality audit of your email addresses.