Hi,

This is the best I can do for having a schema.xml matching the needs of an email user. Use case on Solr 7.5.0

(note : this does not solve any of the bugs previously mentionned, but at least, the logic of Solr is back on track)

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<?xml version="1.0" encoding="UTF-8"?>
<schema name="dovecot" version="2.0">
<uniqueKey>id</uniqueKey>
<fieldType name="gjtext" class="solr.TextField" autoGeneratePhraseQueries="true" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.ClassicTokenizerFactory"/>
<filter class="solr.WordDelimiterGraphFilterFactory" catenateNumbers="1" generateNumberParts="1" splitOnCaseChange="1" generateWordParts="1" splitOnNumerics="1" catenateAll="1" catenateWords="1" preserveOriginal="1"/>
<filter class="solr.FlattenGraphFilterFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.TrimFilterFactory"/>
<filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.TrimFilterFactory"/>
<filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
</analyzer>
</fieldType>
<fieldType name="gjfield" class="solr.TextField" autoGeneratePhraseQueries="true">
<analyzer type="index">
<tokenizer class="solr.ClassicTokenizerFactory"/>
<filter class="solr.NGramFilterFactory" minGramSize="3" maxGramSize="25"/>
<filter class="solr.TrimFilterFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.TrimFilterFactory"/>
<filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
</analyzer>
</fieldType>

<fieldType name="string" class="solr.StrField"/>
<field name="_version_" type="string" indexed="true" stored="true"/>
<field name="bcc" type="string" indexed="false" stored="false"/>
<field name="body" type="gjtext" indexed="true" stored="false"/>
<field name="box" type="string" indexed="true" required="true" stored="true"/>
<field name="cc" type="gjfield" indexed="true" stored="false"/>
<field name="from" type="gjfield" indexed="true" stored="false"/>
<field name="hdr" type="string" indexed="false" stored="false"/>
<field name="id" type="string" indexed="true" required="true" stored="true"/>
<field name="subject" type="gjtext" indexed="true" stored="false"/>
<field name="to" type="gjfield" indexed="true" stored="false"/>
<field name="uid" type="string" indexed="true" required="true" stored="true"/>
<field name="user" type="string" indexed="true" required="true" stored="true"/>
</schema>