All-in-one add-in for outlook

Question

I want to develop all-in-one add-in for Outlook. This means that this add-in will be available for all Outlook clients (desktop, web). I read here that i can do this. I already

Answer 1

Technically you can't make an add-in that will work 100% on all clients. The web-based add-ins currently only work with Mailboxes hosted on Office 365 or Exchange 2013 or greater, and with Outlook 2013 or greater. Outlook.com integration is coming this spring. COM/desktop add-ins work with Outlook 2000-2016, but not in OWA.

To deploy an add-in you need to either publish it to the Office Store or an Exchange Server. See here for more info: https://msdn.microsoft.com/en-us/library/office/fp123515.aspx.

To install a self-published add-in that is not in the Office Store you just add the manifest file from the "Manage add-ins" page in OWA: https://msdn.microsoft.com/en-us/library/office/fp142256.aspx

Note also that you must host your web add-in code in your own web server, and secured with an SSL certificate.