

The Send/Receive errors in Outlook 365 usually occur due to system crashes, abrupt shutdowns caused by power failure, or any hardware/software-related problem. In such cases, users can neither send nor receive emails, leading to Outlook being stuck at updating the Inbox and Outbox folders issue. However, Outlook cannot update the mail items to or from the mailbox server when synchronization fails. The changes made in Outlook are stored in the OST file and synchronized frequently with the mailbox server and vice-versa.

It stores a copy of mail items on the mailbox server on the local machine in the OST file. Outlook 365 works on two-way synchronization.
