The issue occurs in Microsoft Filtering Management Service which filters the mail for any virus or malware. This is mainly due to the date can’t be converted to long integer as the current date is greater than long int and due to this mails might be stuck in queue. And Microsoft has released fixes for the same but it might be take some time to fully implement the update depending on the size of organization. And there are some temporary solutions which could be run to fix the issue as shown below
Since only FIP-FS component is affected, you can disable the components by running the below powershell commands on the server. This would disable Malware scanning as of now but more permanent method would be to follow the Microsoft updates shown below
Set-MalwareFilteringServer -Identity -BypassFiltering $true
Restart-Service MSExchangeTransport