Elasticsearch 5.1: applying additional filters to the "more like this" query - elasticsearch

Question

Building a search engine on top of emails. MLT is great at finding emails with similar bodies or subjects, but sometimes I want to do something like: show me the emails with similar content to this one, but only from joe#yahoo.com and only during this date range. This seems to have been possible with ES 2.x, but it seems that 5.x doesn't allow allow filtration on fields other than that being considered for similarity. Am I missing something?
i still can't figure how to do what i described. Imagine I have an index of emails with two types for the sake of simplicity: body and sender. I know now to find messages that are restricted to a sender, the posted query would be something like:
{
"query": {
"bool": {
"filter": {
"bool": {
"must": [
{
"term": {
"sender": "mike#foo.com"
}
}
]
}
}
}
}
}
Similarly, if I wish to know how to find messages that are similar to a single hero message using the contents of the body, i can issue a query like:
{
"query": {
"more_like_this": {
"fields" : ["body"],
"like" : [{
"_index" : "foo",
"_type" : "email",
"_id" : "a1af33b9c3dd436dabc1b7f66746cc8f"
}],
"min_doc_freq" : 2,
"min_word_length" : 2,
"max_query_terms" : 12,
"include" : "true"
}
}
}
both of these queries specify the results by adding clauses inside the query clause of the root object. However, any way I try to put these together gives me parse exceptions. I can't find any examples of documentations that would say, give me emails that are similar to this hero, but only from mike#foo.com

Answer 1

You're almost there, you can combine them both using a bool/filter query like this, i.e. make an array out of your filter and put both constraints in there:
{
"query": {
"bool": {
"filter": [
{
"term": {
"sender": "mike#foo.com"
}
},
{
"more_like_this": {
"fields": [
"body"
],
"like": [
{
"_index": "foo",
"_type": "email",
"_id": "a1af33b9c3dd436dabc1b7f66746cc8f"
}
],
"min_doc_freq": 2,
"min_word_length": 2,
"max_query_terms": 12,
"include": "true"
}
}
]
}
}
}