Plain text avoids remote content
Email HTML can contain tracking images and external resources. The viewer extracts text rather than displaying the original HTML document. Attachment links download files; they do not execute or preview active content automatically.
Know when bytes change
Individual EML input is included byte-for-byte in the export. MBOX messages have envelope separators removed, line endings normalized and escaped From lines restored. MSG messages become new MIME messages, which preserve useful content but not every Outlook property.
For legal evidence or archival authenticity, retain the untouched original and use a dedicated forensic workflow. This tool is a local reading and extraction utility, not an authenticity certificate.
Inspect the selection before sharing it
A search for example.com can match a sender, a recipient or a body passage; it does not necessarily select only mail from that domain. Review the result table and a few message previews before downloading. The CSV includes subjects and addresses, and the EML ZIP includes message bodies and attachments, so the resulting archive can contain private material even though processing happened locally.
Spreadsheet exports neutralize string values that begin with formula characters, including after leading whitespace. That reduces the risk of a subject or sender being interpreted as a formula when opened in a spreadsheet. It does not make the archive non-sensitive or remove personal information from the content.
Keep original evidence separate from readable copies
MBOX conversion removes envelope separators and restores escaped From lines under the supported mboxrd convention. That creates useful individual messages but changes the container representation. MSG conversion changes more because it builds a portable MIME message. If you need byte-level provenance, retain the original file and calculate its hash with a separate integrity workflow. The viewer neither verifies email authentication signatures nor proves who sent a message.