In the Invite User page, you can add multiple emails and separate the email addresses with a comma, no need to add them one by one.
It is not possible to import the users from your side, but if your requirement is to import them, you can raise a support case from https://support.atlassian.com/contact/#/ and one of our technical support engineers can help you and use a REST API script from our side to import the users. For this, we will need a file with the users' email address, username and display name.
When using an Atlassian account that is not managed, it’s possible to change the email address, but we often receive the following notification on the email that we want to use: Sorry, we couldn'...
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