Troubleshooting Tip: Outlook Desktop (macOS) not working when connected to FortiSASE

[jie]

Description	This article describes how to resolve the issue when a macOS client is connected to SIA via FortiSASE, and the Outlook Desktop client is unable to send or receive emails.
Scope	FortiSASE, FortiClient.
Solution	After connecting the VPN tunnel to FortiSASE, emails in the Outlook app remain in the outbox. When checking Office 365 online, the emails appear to have been sent successfully. Disconnecting the VPN immediately sends the emails from the Outlook outbox.  The issue does not occur with Office 365 web-based login and it is specific to macOS machines. Exempting the Microsoft Outlook traffic from SSL deep inspection. Issue still occurs with sending emails from the Outlook app. Go under Configuration -> Security -> Web Filter profile: Set below URL from 'ALLOW' to 'EXEMPT': *.office.com* *.office365.com* *.microsoftonline.com* *.sharepoint.com* Close the Outlook desktop, reopen it, and select the Send/Receive option from the menu again and all the detained sent emails now appear to have been sent successfully.