Most Report Sets are sent out correctly; however some return "Error sending email, StatusCode: GeneralFailure" in the outbound email logs.
There was no issue prior to VSA v6.3.
The issue is related to the fact that Kaseya VSA V6.3 uses Microsoft .NET Framework 4.0 that uses the "System.Net.Mail.SmtpClient" class. If the email attachment is larger than 3 MB you will get error “Error sending email, StatusCode:GeneralFailure”
Microsoft has issued Patch KB2183292 to correct this error.
Although this patch is dated back to 2010, Please ensure that your system have the latest patch.