title: Fetch messages filtered by conversationId via Office365 API
body: <p>I'm having some trouble figuring out how to use the office365 api to fetch messages given a <code>conversationId</code>.</p>
  
  <p>Let's say my conversationId is <code>AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow=</code></p>
  
  <p>I'll make a request like</p>
  
  <pre><code>https://outlook.office.com/api/v1.0/me/Messages?$filter=ConversationId%20eq%20AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow=
  </code></pre>
  
  <p>This results in a <code>400</code> response like this:</p>
  
  <pre><code>{
    "error": {
      "code": "RequestBroker-ParseUri",
      "message": "Syntax error at position 98 in 'ConversationId eq AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow='."
    }
  }
  </code></pre>
  
  <p>I tried other things, such as url encoding the conversationId to <code>AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow%3D</code> which results in the same error. </p>
  
  <p>I also tried simply removing the <code>=</code> which seems to be the character that is freaking it out</p>
  
  <pre><code>https://outlook.office.com/api/v1.0/me/Messages?$filter=ConversationId%20eq%20AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow
  </code></pre>
  
  <p>but that results in the following error</p>
  
  <pre><code>{
    "error": {
      "code": "RequestBroker-ParseUri",
      "message": "Could not find a property named 'AAQkADlkOGJmMTFmLTc2NjMtMKL3My04ZDhkLTVmZWNjMzA1ODY0NAAQAB11Xh2opSpBiXifMEJjhow' on type 'Microsoft.OutlookServices.Message'."
    }
  }
  </code></pre>
  
  <p>I've also tried messing with the url capitalization and using <code>+</code> signs instead of <code>%20</code> for the filter string, but I consistently get 400 errors back.</p>
  
  <p>I am able to filter by other fields though. For example </p>
  
  <pre><code>https://outlook.office.com/api/v1.0/me/Messages?$filter=IsRead%20eq%20true
  </code></pre>
  
  <p>returns messages filtered as I would expect.</p>
  
  <p>Any idea what could be going on with the <code>ConversationId</code> filter?</p>