Not all sent emails synced to JIRA Service Desk Inbox

[Muhammad Mustafa]

I am connecting my Jira Service Desk to an Outlook inbox, which is showing no issues with the connection based on the Jira email testing tool. However, some emails are skipped and not sent from the inbox to the Jira Service Desk tickets queue. The issue happens occasionally, and even if the same sender sends follow-up replies to the same email, JIRA Service Desk don't sync it. Any body experienced the same?

Thanks!