I am building a test Outlook web add-in using office.js. The add-in uses the itemSend event to check various aspects of a message the user is sending. The event works fine. However, if the web server become unavailable, the add-in completely prevents sending any email at all. I cannot find any way around this. I’ve tried several different ways of trying to first check if the web server is available. Nothing works.

Apparently, Microsoft has disabled itemSend if the web server is not available. But this makes any web add-in developed with itemSend completely unusable because sending email would be shut down for thousands of employees across a company. The fact is that if this is the case, then we have to stick with COM add-ins which are not supported in the confused array of clients aside from classic desktop. Clearly, the office.js approach is nowhere near ready for large scale business use.

Does anyone have any information on whether Microsoft is aware of this and has plans to correct it?