Unique emails in string
<p>I have a string with emails, some duplicated. For example only:</p>

<pre><code>"aaa@company.com,bbb@company.com,aaa@company.com,bbb@company.com,ccc@company.com"
</code></pre>

<p>I would like string to contain only unique emails, comma separated. Result should be:</p>

<pre><code>"aaa@company.com,bbb@company.com,ccc@company.com"
</code></pre>

<p>Any easy way to do this?</p>

<p>P.S. emails vary, and I don't know what they will contain.</p>