Yes. If you don't have Outlook installed, you can use a tool that supports direct IMAP migration to import PST to Roundcube . I used Advik PST File Converter, added my PST file, selected IMAP as the destination, and entered my email account details. After the migration finished, all my emails were available in Roundcube automatically since it syncs with the mail server. It was much easier than trying to do it manually.