server/protocols/protocols-imap4/src/main/resources/imapserver.xml

<?xml version="1.0"?>
<!--
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  or more contributor license agreements.  See the NOTICE file 
  distributed with this work for additional information        
  regarding copyright ownership.  The ASF licenses this file   
  to you under the Apache License, Version 2.0 (the            
  "License"); you may not use this file except in compliance   
  with the License.  You may obtain a copy of the License at   
                                                               
    http://www.apache.org/licenses/LICENSE-2.0                 
                                                               
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  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       
  KIND, either express or implied.  See the License for the    
  specific language governing permissions and limitations      
  under the License.                                           
 -->

<!-- See http://james.apache.org/server/3/config.html for usage -->

<imapservers>

  <imapserver enabled="true">

    <jmxName>imapserver</jmxName>
    <bind>0.0.0.0:143</bind>
    <connectionBacklog>200</connectionBacklog>

    <tls socketTLS="false" startTLS="false">
      <keystore>file://conf/keystore</keystore>
      <secret>yoursecret</secret>
      <provider>org.bouncycastle.jce.provider.BouncyCastleProvider</provider>
    </tls>
 
    <!-- Disallow plain authenticate / login. So any client will need to STARTTLS before try to login -->
    <!-- or the socket must be using TLS in general -->
    <plainAuthDisallowed>false</plainAuthDisallowed>
 
    <!-- COMPRESS extension -->
    <compress>false</compress>
 
    <!-- Maximal allowed line-length before a BAD response will get returned to the client -->
    <!-- This should be set with caution as a to high value can make the server a target for DOS! -->
    <maxLineLength>65536</maxLineLength>
  
    <!-- 10MB size limit before we will start to stream to a temporary file -->
    <inMemorySizeLimit>10485760</inMemorySizeLimit>
    <handler>
      <connectionLimit> 0 </connectionLimit>
      <connectionLimitPerIP> 0 </connectionLimitPerIP>
    </handler>

    <!-- Allow disabling the heartbeat handler -->
    <ignoreIDLEUponProcessing>true</ignoreIDLEUponProcessing>

  </imapserver>

</imapservers>