I have a Yahoo Mail account that has accumulated years of emails, attachments, and custom folders. The mailbox is becoming difficult to manage, and I want to free up server space without permanently losing important messages. Is there a reliable way to create a complete backup first and then remove older emails from Yahoo?

One practical approach is to backup Yahoo emails locally before cleaning the mailbox. This gives you a separate copy that can be retained on a computer or external storage and accessed later when required.

The SysInfo Yahoo Backup Tool provides several options for this type of task. It can connect to a Yahoo account through IMAP/POP3 authentication and lets users select Inbox, Sent, Drafts, Trash, custom folders, and subfolders before starting the backup. It also supports filtering emails by date, which is useful if you only want to archive older correspondence. 

The software supports saving Yahoo emails in formats such as PST, MBOX, EML, MSG, PDF, JSON, DOC/DOCX, and CSV. Attachments can also be handled according to the selected export settings. This means you can choose a format based on how you plan to access the archived emails later.

Another useful option is the Free Server Space feature. According to the product documentation, users can move messages to Trash or delete them permanently after creating the required backup. The tool also provides duplicate removal based on Subject, From, To, and Body, which can help reduce unnecessary copies before archiving.

For large mailboxes, I would recommend first exporting a small date range, checking the resulting files and attachments, and reviewing the migration report. The software provides real-time progress and reports showing completed, skipped, and failed items.

This approach is safer than simply deleting old Yahoo emails because you maintain an independent archive while gradually reducing mailbox storage.