When sending funds via Interac e-Transfer from your Vault account to an external account, you have the option to email your recipient a payment confirmation. However, the actual transaction will appear as being sent from Zum Rails, not Vault.
If your recipient hasn’t received the funds, please ask them to check their email (including spam/junk folders) for a notification from Interac about Zum Rails.
If they still haven’t received it, verify that the recipient’s email address is correct and that their bank supports Interac e-Transfers.