Delaying/Greylisting
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Delaying/Greylisting FAQs
Delaying/Greylisting Configuration
based upon version 1.3.5(9.18) Enable Delaying/Greylisting (EnableDelaying) Enable Greylisting as described at Greylisting-whitepaper. It's a new method of blocking significant amounts of spam at the mailserver level, but without resorting to heavyweight statistical analysis or other heuristical approaches.
Whitelisted Greylisting (DelayWL) Enable Greylisting for whitelisted users.
NoProcessing Greylisting (DelayNP) Enable Greylisting for noprocessing users.
Spam-Lovers Greylisting (DelaySL) Enable Greylisting for Spam-Lovers.
Add X-Assp-Delayed Header (DelayAddHeader) Add X-Assp-Delayed header to header of all delayed or whitelisted emails.
Embargo Time (DelayEmbargoTime)
Enter the number of minutes for which delivery, related with new 'triplet' (IP address of the sending host + mail from + rcpt to), is refused with a temporary failure. Default is 5 minutes.
Wait Time (DelayWaitTime)
Enter the number of hours to wait for delivery attempts related with recognised 'triplet'; delivery is accepted immediately and the 'tuplet' (IP address of the sending host + sender's domain) is safelisted. Default is 28 hours.
Expiry Time (DelayExpiryTime)
Enter the number of days for which whitelisted 'tuplet' is considered valid. Default is 36 days.
Use IP Netblocks (DelayUseNetblocks) Perform the IP address checks of the sending host based on the /24 subnet it is at rather than the specific IP. This feature may be useful for legitimate mail systems that shuffle messages among SMTP clients between retransmissions.
Normalize VERP Addresses (DelayNormalizeVERPs) Some mailing lists (such as Ezmlm) try to track bounces to individual mails, rather than just individual recipients, which creates a variation on the VERP method where each email has it's own unique envelope sender. Since the automatic whitelisting (called savelisting to make a difference to the standard whitelisting) that is built into Greylisting depends on the envelope addresses for subsequent emails being the same, the greylisting filter will attempt to normalize the unique sender addresses, when this option is checked.
Use MD5 for DelayDB (DelayMD5) Message-Digest algorithm 5 is a cryptographic hash function and adds some level of security to the delay database. Must be set to off if you want to list the database with DelayShowDB/DelayShowDBwhite.
Show Delay/Greylisting Database (DelayShowDB)
The directory/file with the delay database file. If you change the filename in section Filepath you must change it here too.
Show Delay/Greylisting Save Database (DelayShowDBwhite)
The directory/file with the save delay database file. If you change the filename in section Filepath you must change it here too.
Expire Spamming Safelisted Tuplets (DelayExpireOnSpam) If a safelisted 'tuplet' is ever associated with spam, viri, failed rbl, spf etc, it is deleted from the safelist. This renews the temporary embargo for subsequent mail involving the tuplet.
Clean Up Delaying Database (CleanDelayDBInterval)
Delete outdated entries from triplets and safelisted tuplets databases every this many seconds. Note: the current timeout must expire before the new setting is loaded, or you can restart. Defaults to 1 hour.
Don't Delay these IPs* (noDelay)
Enter IP addresses that you don't want to be delayed, separated by pipes (|). There are misbehaving MTAs that will not be able to get a legitimate email through a Greylisting server because they do not try again later. An INCOMPLETE list of such mailers is available at cvs.puremagic.com/viewcvs/Greylisting/schema/whitelist_ip.txt. When using mentioned list remember to add trailing dots in IP addresses which specify subnets (eg. 192.168 -> 192.168. ). For example: 127.0.0.1|192.168.
Reply Code to Refuse Delayed Messages (DelayError)
SMTP reply code to refuse delayed messages. Default: 451 4.7.1 Please try again later
