We are looking for an email solution that can securely send sensitive documents to investors, and we would like to learn about specific practices that have worked well in your work. Our core requirement is to minimize the operational burden on investors while ensuring security—for example, we do not want them to need to remember additional passwords or undergo complex verification. Currently, we have over 400 investors, so we need a security mechanism that is both efficient and reliable.

At this stage, our approach is to set an individual open password for each outgoing PDF file. However, as the number of investors increases, this process has become extremely time-consuming and difficult to scale. We look forward to a more automated solution that can maintain the confidentiality of file transmission while simplifying the process for both senders and recipients.

Specifically, we focus on the following key points:

  • Security: Ensure that files are not accessed without authorization during transmission and storage, and comply with industry regulatory requirements.
  • Ease of use: Investors do not need to create new accounts or remember additional passwords; ideally, they can securely view files directly through their common email.
  • Scalability: The solution must support batch sending to 400+ investors and track file access status.
  • Efficiency: Reduce manual operations, such as automatic encryption, link expiration control, or access permission management.

We have considered using encrypted email services or secure file sharing platforms, but we have not yet determined which solution can meet all the above requirements simultaneously. If you have successful experience in similar scenarios, or know of certain tools (such as link-based encrypted delivery, watermarked PDFs, or encryption plugins integrated into email clients), we welcome you to share specific details.

Thank you for your time and suggestions!