Then check the internet connection and firewall settings. To troubleshoot the issue, try reconnecting the network cable or WLAN.

Similarly, if the mailbox server is down, it can prevent Outlook from synchronizing the mail items. An unreliable and poor network connection or firewall settings can obstruct Outlook from synchronizing the mail items stored in the IMAP OST file to the mailbox server.

Synchronization requires an active network connection with the mailbox server. Methods to Resolve IMAP Sync Issue in Outlook 2019, 2016, or 2013īelow we have discussed some methods to troubleshoot and fix Outlook 2019, 2016, or 2013 Sync Issues. Check your system for these security updates and uninstall them. NOTE: Security Updates KB2837618 or KB2837643 cause problems, such as synchronization issues in the Outlook IMAP account. Thus, fixing the IMAP Sync Issues is critical.

Sync errors while manually synching the mail items from IMAP OST to the mailbox server.

Mismatch in number of emails between Outlook and webmail.

Failure in sending or receiving new emails.

However, the Sync issues in the Outlook IMAP account may also arise due to the following reasons,ĭue to slow or no synchronization between the Outlook client and mailbox server, users may experience problems, such as, The Synchronization errors and issues in Outlook 2019, 2016, or 2013 usually occur due to damaged or corrupt Outlook data files, i.e., OST (Offline Storage Table). But sometimes, you may experience synchronization issues in Outlook that can lead to errors and prevent users from sending or receiving new emails. With proper settings and configuration, the synchronization between the Outlook client and mailboxes server ensures uninterrupted email flow. Any changes made, such as drafting a new email or deleting messages, etc., are stored in the Offline OST file and synchronized with the mailbox server. When configured with an IMAP-based email account, Outlook creates an OST Outlook data file to store an offline synchronized copy of mail items, such as emails, contacts, attachments, notes, tasks, etc. Methods to Resolve IMAP Sync Issue in Outlook 2019, 2016, or 2013.

Outlook 2016 sync issues imap