What is email Verification
(Note: if you didn’t read Part 1 – What is Scrubbing, please do that as well, its very important to understand the full process )
Basically this will tell you if the email is valid or not, a dead email, Hard bounce etc. You NEED to know this because you do not want to mail to this address as all hard bounces affect your send score and inbox and also affect your IP and server reputation or can get you in trouble with a white listed server like Constant Contact or Mailchimp !
A good email verification will basically replicate sending an email, so the verifying server contacts the server of the email address and gets back an SMTP code indicating if it’s a valid email or not.
Now it sounds simple, but there are many SMTP codes that come back so most just convert the codes into OK or Valid, Fail or Invalid and Unknown to make things simpler.
OK or Valid – is basically that, it’s a good email, no worries, mail away.
Fail or Invalid – this is a dead, hard bounce, invalid email, Do Not mail to this address it will bounce back.
Unknown – there are a few reasons for this ranging from verification is not allowed on some servers, so they know your trying to verify so they won’t confirm or not. Some servers are just down so the verifier can’t complete the task so that’s unknown etc. Now if an email is invalid or dead, you would get back another SMTP code (550) to indicate that so in the event of a server that does NOT allow email verification, it’s a safe bet that the email is ok (as that server would give you a 550 code or invalid email code).
I think typically around 80% – 85% of all Unknown emails are probably ok to email to, but you decide on that when you get back your results.
Email Verification simply examines and communicates with the SMTP server of each email address in your list and will tell you if it’s OK or not. NOTHING is removed like in scrubbing and one other important thing to understand. Spam traps, Black holes or honey pots, are all VALID email addresses, so verification will only tell you OK!
So to sum up, I believe you should first Scrub your lists to actually remove the bad KNOWN emails, then you verify them to get as clean a list as possible, if you skip one of these steps you leave it open to retaining bad data and your taking that risk.
NOTE: it’s important to understand that it’s impossible to clean any list 100% and if someone claims that, well they are full of shit! Simply put, millions of spam traps are created each day, millions of emails are abandoned each day, people leave their jobs and their emails accounts get closed. It’s impossible to track this and stay on top of it so it’s impossible to know every spam trap or every email that’s been closed.
Last thing on this same note about email verification, if you get a list scrubbed and verified today, the results will be different tomorrow for these same reasons, so understand if you clean your list then mail it out in 2 weeks or a month, you may very well end up with an additional 5% hard bounce rate because things change all the time.