Your emails can get stuck in Outbox if the mail server is offline. Top 4 Solutions to 'Email Stuck in Outbox' Issue in Outlook 2016/2013/2010 1Change Outlook Connection Status getting scanned by an antivirus tool, then it could cause the emails in the Outbox to get stuck. If Outlook is being used by another program e.g.The email sending process can get stuck if your Outlook send/receive settings are incorrect.
To fix this, you will need to get it authenticated by the mail server. The large size of attachment usually slows down the sending but it can also sometimes completely halt it. Following are some of the common reasons: There could be a number of reasons behind this issue. Reasons Why Outlook Emails Stuck in Outbox
