WFFM Duplicate Emails - CM and CD servers processing Send Message events

Question

Sitecore.NET 9.0.2 (rev. 180604)
Web Forms for Marketers 9.0.rev. 180503

I have one content management server and two content delivery servers that are in a DMZ. Users from the internet interact with my CD servers.

I'm getting duplicate emails when someone submits a form from WFFM. It seems that both my ContentManagement and the ContentDelivery server that produced the event are sending an email. I've verified this by looking at the email headers and I can see that I get an email originating from the CD server that took the original request and an email from my CM server.

In my test environment, I only have one CM and one CD server. With the same configuration, I'm not able to duplicate the multiple emails. The CM server seems to always be producing the emails. Though as a side note. I did shut down IIS on my CM in test and I noticed that the CD server processed the event and sent an email.

When I do show config layers on my CM instance and set the role to CD I'm not seeing wffm:action:remote... so what's telling my CD instances to process the sendmessage/email event? It looks like the <setting name="WFM.IsRemoteActions" value="true" /> should be getting brought in.

Is this some kind of race condition magic?

Answer 1

I think there might be another setting you need to make sure is totally removed on CM servers...

<setting name="WFM.IsRemoteActions" value="true" /> 

This should only be present on CD and possibly Processing (if you have that) from memory. It's all in the Installation Guide somewhere I'm sure that's where I read it :)