Data protection breach in e-mail use based on case studies
1st case CC instead of BCC
If you send an e-mail to several recipients and the recipients can see each other (CC and not BCC), this would be a data protection violation if the e-mails are not publicly discoverable with first and last name in the address.
Report data protection incident to competent data protection authority and apologize to recipients
2nd case the wrong recipient
When sending an email with content that includes personal data, an incorrect recipient, is a data breach.
Report data protection incident to the competent data protection authority, as well as apologize to recipients and data subjects.