Some of my MSG emails contain tables, clickable links, signatures, inline images, and formatted text. After conversion, I need them to open properly in EML-supported mail clients. Plain or broken message body will not work because these emails are part of office records.
HTML emails can look broken after MSG to EML conversion when the original HTML body is not read properly. Outlook MSG emails may include tables, signatures, inline images, fonts, links and character encoding details. If any of these parts are skipped during conversion, the EML file may open with disturbed spacing, missing images or plain-looking text in Thunderbird or Apple Mail.
Do not solve this by renaming .msg to .eml. That only changes the file extension and can make the email layout worse.
If you want a safer local way to handle HTML-heavy MSG emails, you can check DataVare MSG to EML Converter Expert. It gives a preview before export and helps keep formatting, attachments, mail fields, and EML output on your system without needing Outlook.Try a few emails with tables, signatures, and inline images first. If those open correctly in Thunderbird, then continue with the rest of the MSG folder.