Kevin,

Several months ago in earlier version we had the following issue, which has long been fixed:

// New to VersionNumber = '2.6.3.487';
{TODO -cFix : Again still, when emails were over the MaxMsgSize limit, the sender was sometimes disconnected without outputting a numeric error code, causing them to retry }

The only solution for this was to to wait until the sender has completely sent the message in full, and then SpamFilter would output a 5xx error code rejecting the email (as it does with all other filters). There is not a setting to enable/disable the generation of NDRs for this filter. It's either enabled or disabled.

Please note that SpamFilter never sends NDRs, it simply outputs an error code to the sender's SMTp server, which forces the *sender* to
generate and send an ndr to their user (thus saving your bandwidth and resources). The only time SpamFilter sends NDRs is when it has trouble forwarding a "clean" email to your SMTP server (mailbox full, user no longer exists, and similar problems).

Is it possible for us to send you a large email so we can verify remotely your install? If so, can you email us the address to use and your current limit?

PS -
Before we were outputting an error code and forcing a disconnect on the remote server *before* they were done sending the email, as soon as the size limit was reached. We found however some mail servers that would not "listen" for errors until they were done sending the whole message.

Sure. Please find them below. (Hint - if you delete a value from the SpamFilter.ini file, start SpamFilter, and click on "Save Settings", the values will be re-generated).

[Error Response]
ResponseBlacklistedMAPS=521 The IP %IP% is Blacklisted by %MAPSResponse%.
ResponseBlacklistLocalIP=521 The domain %Domain% is Blacklisted.
ResponseBlacklistLocalDomain=521 The domain %Domain% is Blacklisted.
ResponseNoReverseDNS=550 Your IP %IP% does not have a reverse DNS entry. Disconnecting...
ResponseMaxRCPTTO=550 You exceeded then maximum number of RCPT TO. Disconnecting...
ResponseCountryBlacklist=550 Your IP address is from a blacklisted country. Disconnecting..
ResponseRelayRestricted=550 You are not allowed to send mail to %EMailTo%
ResponseBlacklistLocalEMail=521 The EMail %EMailFrom% is Blacklisted.
ResponseKeywordMatch=557 This email is rejected. It contains keywords rejected by the antispam content filter.
ResponseBlacklistLocalEMailTo=521 The EMail %EMailTo% is Blacklisted.
ResponseMaxIncomingMsgSize=552 This email is rejected. It exceeds the maximum allowed message size.
ResponseNoMX=550 Your domain %Domain% does not have a valid MX DNS record. Disconnecting...
ResponseBlacklistedSURBL=521 A URL in the email is Blacklisted by SURBL: %MAPSResponse%.
ResponseVirusFound=557 This email is rejected because it contains a virus
ResponseSPF=550 The sender did not meet Sender Policy Framework rules. Please see http://spf.pobox.com
ResponseIPCacheBlacklist=421 Your IP is temporarily blocked, please try again later.
ResponseSpamImage=557 This email is rejected. It contains content rejected by the antispam filter.
ResponseSFDB=557 Your IP %IP% is currently listed in SpamFilter ISP's Distributed Blacklist. Please see http://www.logsat.com/SFDB/why.asp for details.