Final answer:
Since Vine was discontinued in 2017, finding a Vine username with an email is no longer possible through official means. You could check old emails for correspondence from Vine that might mention your username or use a third-party archiving service with caution.
Step-by-step explanation:
Finding a Vine username with an email is not straightforward as Vine, the short-form video hosting service, was officially discontinued in 2017. If you were attempting this while the service was active, you would typically use the password recovery or search function within the Vine app or website, where you could request to recover your account details using your email address. This would then send an email to the address on file, potentially including your username.
However, in the current scenario, your best bet to find any associated username would be to check any old emails from Vine for mentions of your username or to use a third-party service that archives usernames. Please remember to respect privacy and never attempt to access someone else's account without permission.