Outlook C# VSTO Add-In events fired too many times
<p>I'm writing an add-in for Outlook 2013. Emails in our company usually ends with number of conversation item like <code>note.04</code>. If user has to reply to one of these messages he or she has to manually increment the number. I want to automatize this process.</p>

<p>I'm using 2 events to achieve this: <code>ExplorerEvents_10_SelectionChangeEventHandler</code> and <code>ItemEvents_10_ReplyEventHandler</code>. The thing is these events are fired more than once. The first one has fired 3 times on just Outlook startup and the second one has fired 2 times after I clicked "Reply" button. The result is that when message contains <code>note.04</code> and I click reply, the number is increasing too many times, e.g. <code>note.07</code>.</p>

<p>How can I make sure this events occur only once?</p>