How does Mimecast enhance the security of large email attachments?

Mimecast enhances the security of large email attachments primarily by allowing secure delivery through protected drop boxes instead of regular email transmission. This method offers several advantages. First, it limits the risk associated with sending large files over email, which can often be intercepted or compromised during transit. By using protected drop boxes, Mimecast ensures that only authorized recipients can access the files, thereby adding an extra layer of security to the delivery process.

Additionally, this approach helps alleviate issues related to email size restrictions that many email service providers enforce, allowing for seamless sharing of large files while maintaining robust security protocols. Protected drop boxes are also equipped with features such as password protection and expiration settings, further safeguarding sensitive data.

The other methods suggested do not provide the same level of security or functionality regarding large attachments. For instance, compressing attachments might reduce file size but doesn't inherently secure the content. Automatically deleting attachments after a week does not help with immediate security during the transmission process, and simply converting files to PDF does not address potential vulnerabilities present in the original file format during transit. Hence, the use of secure delivery through protected drop boxes stands out as the most effective and comprehensive solution in securing large email attachments.