As always, this upgrade is free for all users with a current software maintenance.
The full list of changes since the latest official release (4.7.3.217) is as follows:
// New to VersionNumber = '4.7.4.241';
{TODO -cNew : Added entries in activity logfiles to indicate when SpamFilter starts the routine process of removing old emamils from quarantine database (Starting TDeleteExpiredQuarantineThread) }
{TODO -cFix : Added support for BIGINT data type for the fields tblQuarantine.QuarID, tblQuarantine.MsgID, and tblMsgs.MsgID. This is needed if admins experience would experience an overflow when using the default INT data type for those fields}
{TODO -cFix : If the Blacklist Cache IP blocking filter is enabled, disabling it would still cause SpamFilter to check new inbound connection against the IPs present in the cache until they eventually age out a few minutes later (IPs for new connections will however not cause the IPs to be blacklisted in the cache - there was no bug in this behavior) }
// New to VersionNumber = '4.7.4.239';
{TODO -cFix : Disabled the advertising of BINARYMIME in the EHLO banner as that extension can only be used with CHUNKING (which is not available in SpamFilter)}
{TODO -cFix : Issue introduced in 4.7.4.232 - Running the standalone version of SpamFilter.exe did not automatically launch SpamFilter with elevated privileges - users had to manually "launch as administrator" the standalone version for it to work properly}
{TODO -cNew : Changed the behavior of the filter order - if a recipient is not in the "Authorized TO Emails", that recipient will be rejected even if a whitelist is active since that adddress is non-existent. If however the connection is being whitelisted, the DisconnectOnNonAuthorizedTO=1 option in the SpamFilter.ini will be ignored and the connection will not be forcefully disconnected}
// New to VersionNumber = '4.7.4.236';
{TODO -cFix : Resolved issue during Active Directory and LDAP SMTP Authentication for this error: Account failed: Error Opening Connection to Server}
// New to VersionNumber = '4.7.4.235';
{TODO -cFix : Undid this change in 4.7.3.235, as it may have been causing access violation errors: ---> 4.7.4.234: Increased the max stack size per thread from 1MB to 10MB to help reducing risk of stack overflows}
// New to VersionNumber = '4.7.4.234';
{TODO -cNew : To help troubleshooting, added log entries for when SpamFilter starts and finishes checking an email for keywords}
{TODO -cFix : Complex RegEx expressions that caused a large number of recursions can cause SpamFilter to crash abruptly with stack overflows errors which prevent any logging of the cause of the problem}
{TODO -cNew : Added new SpamFilter.ini option MaxRegExLimitRecursion to prevent stack overflow crashes when using complex RegEx expressions}
{TODO -cFix : Increased the max stack size per thread from 1MB to 10MB to help reducing risk of stack overflows}
// New to VersionNumber = '4.7.4.232';
{TODO -cFix : Starting from v4.7.3.217 a bug was introduced that prevented SpamFilter from looking at the "text/plain" section of the email, and only examined the html and decoded sections}
// New to VersionNumber = '4.7.4.231';
{TODO -cFix : Added an option in the "Customized Items" tab to specify a custom reject notice for emails blocked by the attachment filter. Previously the same rejection notice used by the keyword filter was also used by the attachment filter}
// New to VersionNumber = '4.7.4.230';
{TODO -cFix : Added SpamFilter.ini option SkipSPFWhenCheckingFromHeader - allows to optionally skip the SPF test of the From: header if using the option (disabled by default) to also test the email in the "From:" header in addition to the MAIL FROM against all blacklists/whitelistss/SPF (the SPF standard only recommends to test the MAIL FROM, not the From: header)}
// New to VersionNumber = '4.7.3.225';
{TODO -cFix : Regression error bug introduced in 4.7.2.184 that re-introduced a bug fixed in 4.7.1.150: If a DNS server is offline, SpamFilter will not cause a timeout and switch to a backup DNS server if one was specified}
// New to VersionNumber = '4.7.3.224';
{TODO -cNew : Included the testing of the SPF filter even for addresses specified in the "From:" header, if the new option in 4.7.2.217 is selected (Added an option to include the email address in the "From:" header) }
{TODO -cFix : Bug introduced in 4.7.3.219. The SPF test to incorrectly fail under one scenario: The sender specifies the "mx" mechanism in the SPF TXT record, and the IP address of the sender does not match the IP of the host in the MX record (thus failing the MX record check in SPF). The bug causes the entire SPF check to fail if the above scenario occurs, even if other entries in the SPF test would cause it to pass.}
{TODO -cFix : Some database errors while editing the filtering settings using SpamFilter's GUI could cause application crash screen to appear on screen even if they are harmless-non-critical}
// New to VersionNumber = '4.7.3.222';
{TODO -cNew : When using the option to include the email address in the "From:" header introduced in v4.7.3.217, we are now also comparing the From: header when testing the entries in the AutoWhitelistForceDelivery file}
{TODO -cFix : When using the option to include the email address in the "From:" header introduced in v4.7.3.217, SpamFilter was not logging the fact that the email was being whitelisted when the sender matched due to the From: hedaer}
{TODO -cFix : During an SPF filter TXT record check, if the TXT record is longer than 255 characters, and the DNS server used by SpamFilter has a bug that causes it to respond with a malformed packet (which will be flagged as such during a Wireshark capture), this can cause SpamFilter to max out the CPU and freeze after a few such queries}
// New to VersionNumber = '4.7.3.219';
{TODO -cFix : During an MX filter record check, if a DNS server does not allow SpamFilter to query it, SpamFilter incorrectly treats the error "DNS Server Reports Query Refused Error" as a "DNS Server Reports Query Name Error". As the latter (Query Name Error) indicates a non-existent record, the "Query Refused Error" makes SpamFilter think the MX record does not exist and thus the email is incorrectly rejected}
// New to VersionNumber = '4.7.3.218';
{TODO -cFix : Fixed issue with Bayesian filter introduced in 4.7.3.217: Exception occurred during GetMessageTokens: Error in regular expression at offset 2: unrecognized character after (? or (?- 00b2da8e SpamFilterSvc.exe System.RegularExpressionsCore}