A customer wanted me to set up a library for incoming e-mails. He wanted a simple solution to sort the e-mails in different folders. I thought that this would be an easy task, and it proved that I should never underestimate SharePoint 2010 or Nintex. Ever. Again.
I sent a lot of email and all got saved in this document library. I was kinda proud because everything went really well until I realized: The workflow won't start.
Incoming emails will be moved to a library via System Accounts, which won't trigger a workflow. That means you have to enable this little feature with a little command:
stsadm -o setproperty -pn declarativeworkflowautostartonemailenabled -pv true
And that's it. Now incoming emails will trigger workflows.