I have years of important emails stored in Yahoo Mail, including work conversations, invoices, and messages with attachments. I want to keep a local copy on my computer so I can access these records even when I am not signed in to my Yahoo account. I also need a format that is easy to open and share when required.

My first preference is to save Yahoo email as PDF because PDF files are convenient for reviewing individual messages and maintaining records. However, I do not want to lose email details such as sender information, dates, message content, or attachments during the export process. Saving everything manually would take too much time, especially when several folders contain years of correspondence.

While comparing available options, I came across the SysInfo Yahoo Backup Tool. It supports exporting Yahoo emails into formats such as PDF, PST, MBOX, EML, MSG, and DOCX. The software also provides options to select particular folders, apply date filters, and manage attachments according to the required output. These features could be useful for creating a more organized archive instead of downloading messages individually.

Another thing I need to consider is how to manage duplicate emails and previously exported messages. I would prefer a method that lets me keep the existing archive organized without repeatedly processing the same data. A local copy on an external hard drive would also provide an additional option for keeping important correspondence accessible.

For anyone researching a reliable Yahoo Mail backup method, what has worked best for you? Do you usually export messages as PDF for easy reading, or do you prefer PST or MBOX when you want to preserve emails for future use? I would appreciate suggestions based on actual experience, especially when attachments and folder organization are important.