When I've contacted them a long time ago, they replied to me through
They also said here
OP I hope you not sign up to phishing sites like @Sutters Mill, if you sign up to official blockchain.com [1] and still don't get the verification, this is the solution for you.
First, give it a few minutes. Occasionally, emails can be delayed by as much as 5 minutes. If after 5 minutes you still have not received your authorization email, check your spam folder and filter settings. To prevent your emails getting filtered out, add [email protected] [email protected] as contacts.
If your email is still nowhere to be found, contact your email provider and make sure they’re not blocking our domain or having a system-wide issue with email reception from other domains.
If you have checked with your email provider and verified that our emails are not being blocked and you still have not received your authorization email, please contact our support team so that we can investigate the issue and help you regain access to your wallet.
If you require urgent access to your funds and are not receiving your authorization emails, you can always use your 12-word backup (recovery) phrase to restore your funds in a new wallet, here: https://login.blockchain.com/#/recover. Please note that imported addresses are not backed up by the backup phrase and will not be restored.
[1] https://www.blockchain.com/