Windows VM opens itself when trying to send email from OS X Mail.app

I have a problem that I can't seem to fix and upsets me to the highest level.
I have (2) Windows 8.1 Pro 64 bit VM installed with Parallels Desktop 10 under a MacBook Pro Retina with OS X Yosemite 10.10.3

My main VM is the one with Office 365 (2013) installed. The other VM is installed with Office 2010.
Everything worked fine for quite some time under PD 8-9, OS X Leopard and Mountain Lion.

A little while after upgrading to Yosemite and PD 10, every single time I'm trying to send an email from the Apple Mail.app, it opens up my Windows 8.1 VM, the one with Office 2010, never the other VM with Office 365. While the VM is loading, the Mail.app freezes, only when the VM is properly loaded at the logging screen the Mail.app comes back to life and my email is sent.

I send many emails during the day and as you can imagine, this is very frustrating.

The bizarre thing is I can't see why, or where to change this. I looked everywhere in the config settings of both VM's to see of any differences but I can't see any. It also doesn't seem to be doing this all the time. It will do it 100% if I start from a fresh reboot, but sometime it will, and other times it won't, regardless if the PD was loaded or not during the day after my morning reboot.

I really need your help in fixing this before I go postal.

Any help would be appreciated.
Thank you!

 

Hi Jimmy,
Please check and disable if E mail application is shared with Windows Virtual Machine using Shared Internet Applications Tools following the steps below :

1. Open virtual machine window (Do not click Start).
2. Open virtual machine configuration ( http://kb.parallels.com/117287 ) > switch to Options tab > Applications.
3. Set Web Pages, Email to desired values.
4. For deeper configuration use More Applications button.

 

Thank you for your reply,

I tried that but it doesn't fix the problem.

My Options tab parameters are identical on both VM's but every once in a while (100% after a reboot) I want to send an email using Mail.app it opens only my Office 2010 VM... Very frustrating.