So naturally, if Outlook is taking more time to receive emails, the “ writing to the PST” part is the first place to look for possible problems. Whenever an email is received in your inbox, Outlook takes the default action of writing it to the PST file. Also, learn solutions to fix the issue of Outlook Running Slow on Outlook 2019, 2016, 2013, 2010 & 2007. In most cases, error/damage in the Outlook PST file is responsible for the delay in receiving Outlook emails. Expert’s Opinion: Outlook experts suggest to check the health of Outlook PST file using SCANPST.EXE or a trusted PST recovery software.