A popular question on many forums goes something like this
Outlook isn’t recognized by [application_name]. The error is “Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default client.” When I check the Default Programs, Microsoft Outlook is the default for everything.
First and foremost, when you receive this message with Outlook 2010 or Outlook 2013 64-bit, try the 32-bit version of Office. While some applications and addins work with the 64-bit version, not all do. Unless you need to open large (2 GB) Excel and Access files, you won’t benefit the 64-bit version. Wanting to use the 64-bit version because you use a 64-bit operating system isn’t enough reason to use it, if you need compatibility between different applications, you’ll need to stick with the 32-bit build.