Earlier today we identified a major bug in the system that was used to generate statistics for SPAM email daily and intraday reports for some users. Although the issue affected only a few thousand people, I have chosen to pull it out of the production systems to avoid further confusion and lack of email report integrity. As soon as the bug fix is tested thoroughly, we will be placing it back into production. In the meantime, you will not see “Non SPAM Mail” total under statistics anymore.

Problem Details

ExchangeDefender daily and intraday reports are built using SQL queries against the mail log database. There are three queries executed for each report, one to obtain the SPAM messages, one to obtain SureSPAM messages and one to obtain the total number of rows in the table, both SPAM, SureSPAM and messages let through. Each SPAM query is executed within a check that verifies if the user settings are to store/quarantine junk mail because otherwise we have nothing to report if the messages are delivered and/or deleted. Totals for SPAM and SureSPAM are calculated within the respective settings check blocks. For example:

if (User Quarantines SPAM)
{
    Get SPAM Total
    Print Report
}

if (UserQuarantinesSureSPAM)
{
    Get SureSPAM Total
    Print Report
}

Get Total Messages Received

Not SPAM = Total Messages – SPAM Total – SureSPAM Total

The problem with the Not SPAM count came in if the user did not store/quarantine their SPAM or SureSPAM which would mean the blocks of code that calculate the totals for the group would not get executed. The Non SPAM total would not get the correct amount of SPAM or SureSPAM subtracted from it and it would appear to the user as if they were missing messages because they surely were not receiving the amount that the report had indicated.

Stupidity Details

We figured we could save a few cycles by not running an extra query and total if the users did not store/quarantine SPAM or SureSPAM. Unfortunately, the equation for Not SPAM did not take that check into account and instead of subtracting the correct totals for SPAM and SureSPAM which are still logged but never reported, we were subtracting a zero thereby inflating the Not SPAM total for certain users.

The good news is that it was simple enough to fix, sorry for all the frustration that has come out of this as both my support, my partners and my clients were seeing different results across the network. Considering I am responsible for the above I apologize for all the problems this has caused for you.

Vlad Mazek

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