OST to PST - Version 4.3 Use OST to PST Email Recovery Tool to backup Outlook emails from unreadable OST files. No. of Outlook client face problem on off-line for backup OST to PST emails. As you know - OST files enable on off-line Exchange Server. Use Quick Outlook Email Recovery Tool on this situate to configure unreadable OST files and deeply scan to trace unwanted error from them and bring back Outlook emails on off-line for email client against corrupt Exchange server. Outlook email is not readable on off-line without converting OST into PST files. Outlook expert design great email backup tools that restore emails from unreadable or damage Outlook OST files - created by MS Exchange Server, it is blueprint of personal storage emails but without third party application user cannot browse or configure in personal storage files. Quick Outlook Email Recovery Tool is best third party application used on off-line mode to deeply scan and easily backup lost emails from OST files then converting them into PST files to easily read with Outlook mailbox personal storage files. It is complete email backup solution that