If you delete items from an Outlook Data File (.pst) or Offline Outlook Data File (.ost), Outlook automatically compacts the file in the background during idle time, when you\u2019re not using your computer, but Outlook is still running.<\/p>\n\n\n\n
Note<\/strong>:Outlook only compacts the file if there is more than 20% of ‘white space’ (unused space) in the file.<\/p>\n\n\n\n You can also use the following steps to manually start the compact process immediately, which may take several minutes to complete.<\/p>\n\n\n\n Ref: https:\/\/support.microsoft.com\/en-us\/office\/reduce-the-size-of-your-mailbox-and-outlook-data-files-pst-and-ost-e4c6a4f1-d39c-47dc-a4fa-abe96dc8c7ef#ID0EAABAAA=Newer_versions<\/p>\n","protected":false},"excerpt":{"rendered":" If you delete items from an Outlook Data File (.pst) or Offline Outlook Data File (.ost), Outlook automatically compacts the file in the background during idle time, when you\u2019re not using your computer, but Outlook is still running. Note:Outlook only compacts the file if there is more than 20% of ‘white space’ (unused space) in the file. You Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[10,18],"tags":[],"class_list":["post-3034","post","type-post","status-publish","format-standard","hentry","category-microsoft","category-microsoft-office"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t
Note<\/strong>: If you are using an Exchange or Outlook.com email account, you need to additionally click the Advanced<\/strong> tab > Outlook Data File Settings<\/strong>.<\/li>