We use the token bucket filter for exactly this purpose. https://issues.apache.org/bugzilla/show_bug.cgi?id=45753 We adapted Chad LaVigne's to use for logback and it works well. IMO, a TokenBucketFilter should ship with logback. snipit from one of our xml configs: <appender name="EMAIL" class="com.emiles.util.log.logback.ReverseSMTPAppender"> <BufferSize>128</BufferSize> <SMTPHost>...</SMTPHost> <From>...</From> <To>...</To> <Subject>... %p %m%nopex</Subject> <Evaluator class="com.emiles.util.log.logback.TokenBucketEvaluator"> <TokenFillAmount>2</TokenFillAmount> <TokenFillInterval>300</TokenFillInterval> <MaxTokens>20</MaxTokens> <LogLevel>ERROR</LogLevel> </Evaluator> this will allow a burst of 20 emails followed by a gradual build up of letting 2 more through every 5 minutes. -casey -----Original Message----- From: logback-user-bounces@qos.ch [mailto:logback-user-bounces@qos.ch] On Behalf Of Louie Liu Sent: Monday, June 01, 2009 11:13 PM To: logback-user@qos.ch Subject: [SPAM] - [logback-user] Question - Email found in subject We have the following use case and would like to know what is the best practice in logback framework. Basically, we are trying to use the SMTP logger appender to send alert email when the erorr is occured. The issue is that we would like to generate a summary messages (which including, for example, about 100 errors which occured within the given time frame) and send only one email. The reason for it is to reduce the number of email to avoid flush the email server. Please let us know what is the best way to configure the logback to satisfy the use case above. Thanks a lot. Louie _______________________________________________ Logback-user mailing list Logback-user@qos.ch http://qos.ch/mailman/listinfo/logback-user