In the Visitor Access Settings for both Approved Emails and Multi-Factor, you can list the allowed visitor email addresses to your site in the Approved emails section.
You can enter the email address in two ways, first is by entering it in the given field, or by using the Bulk Edit button:
Using the Approved emails field
You can enter one or multiple email addresses in the field by separating them with commas as seen on the sample given in the field.
The comma will automatically separate the email addresses as seen in the screenshot below.
You can also enter a whole domain (e.g. @acme.com) instead of an email address so all visitors using the domain can be granted access to the site.
Click the Add button to grant access and share the link in a separate email to the users. (See Sending Invites - Customized Message at the bottom of this article to send the invites)
Using Bulk Edit
Bulk Edit should be used if you are entering a list of email addresses. Clicking the Bulk Edit button will show the Bulk Email Editor pop-up. With the Bulk Email Editor, you can make changes to all of your site's allowed visitor emails at once.
The emails you add here will completely replace the currently allowed emails for the site.
It is recommended that you copy emails from a spreadsheet or list and paste them into this editor rather than adding them manually.
Put each email on its own line as seen on the screenshot below, click the Next button once done.
A confirmation window will appear showing you the:
Total - After saving, the total number of emails with access to the site
Adding - After saving, the total number of new emails that will be given access to the site
Removing - After saving, the total number of emails that will lose access to the site
Errors - Total number of errors
Errors field - Shows which encountered an error, otherwise will show "All emails are valid."
Click Back to correct the errors, or click the Save button to keep the allowed email addresses. You should then see all of the allowed email addresses for the site.
Set the Email Token Type by following this article.
Sending Invites - Customized Message
Ticking the box beside Send invitations will allow you to compose an invitation message and send the invite without sending a separate email.
Clicking Add and send email invites button will open this window where you can compose your invitation message (or leave it empty).
Click Send invitation to site to send it to the allowed visitor's email address.
This is what you'll see in the email invite if it has a customized message.