https://www.123articleonline.com/rss/author/253236/thomes-carryArticles written by thomes Carry from 123ArticleOnline.comen-usCopyright (c) 123ArticleOnline.com All rights reserved. https://www.123articleonline.com/articles/1122268/how-to-export-contacts-from-outlook-ost-to-pst-manually OST files are offline files that help users to store Exchange mailbox data and make it available to the users even when the Exchange server is not available.