There are certain email addresses which do not provide a definitive validation result, from any email validation method and from any service, irrespective of the username of the address.
As part of our service we can determine that an email domain exists, is live and is sending and receiving mail. However with unknowns we can’t confirm the username is valid and therefore they should be treated differently from other valid email addresses.
These are typically emails from businesses, government, healthcare and educational institutions.
Absolutely, there is still a lot of value to be taken from this type of email.
Unfortunately no email validation service can distinguish unknowns from valid addresses with 100% certainty. However there will be a strong number of valid addresses in this category that can be used for marketing purposes.
They just need to be handled in a slightly different fashion to the other definitive categories, in order to sieve through the good and bad email types.
Unknowns should be handled slightly differently to the other classifications.
We recommend drip-feeding emails from the unknown category into your email campaigns in small batches.
You can then remove the email addresses that bounce when the campaign is sent and be left with valid email addresses to include on an on-going basis.
As they are only included in small batches, any bounces will have a negligible impact on inbox placement and sender reputation and therefore the success of your email campaign.