I was working on a complex workflow when the notifications suddenly appeared to have stopped working. The workflow would fire and correctly set variables, but never send the email notification. If I added myself to the workflow notification email, it worked, but there were strange characters such as "1" or "#" in the to field.
Turns out, the fix was very simple, but I lost an afternoon trying to figure it out so wanted to post it here.
It appeared at first glance that the notifications that worked and the ones that didn't were identical, set up as follows:
Even if you looked at the workflow email both cases appeared identical:
So, after a good deal of head scratching and some fruitless internet searches, I found the difference between the notifications that worked and the ones that didn't.
By default, when you use a group in the "to" field of the workflow email, it is configured as follows:
However, for groups, this doesn't work! Instead, set the return field as "
Email addresses, Semicolon Delimited" for the group notification to work:
Now my workflow notifications against a group work perfectly.
Like so many things in SharePoint, its a small issue, but difficult to track down if you aren't sure what is causing it. Hopefully this will save you some time!