Currently we aren't offering the in-built Email Validation feature in Growably.
The reason for this is that High-Level charge a high price for the usage of it.
And, because we're giving Growably to our members for free, we can't include something that has a high scaling cost attrached to it.
So, if you're looking for a service to perform Email Validation, then here's a few options:
With these services, you simply upload a copy of your exported Email Contact list and run a validation process.
The vendor will then tell you what emails are valid and what ones aren't.
Then simply remove all the emails from Growably that they have marked as Invalid / Undeliverable.
Easy peasy :-)