Symptoms

Issue:
When trying to send an email using the 'send an e-mail' action rule from a SmartForm, the error 'This property cannot be set to an empty string. Parameter name: value' appears.

Type:
System.ArgumentException
Source:
System
Method Base
Member Type:
Method
Name:
set_Host
Module
Scope Name:
System.dll
Declaring Type
Full Name:
System.Net.Mail.SmtpClient
Stack Trace:

at System.Net.Mail.SmtpClient.set_Host(String value)
at SourceCode.Forms.AppFramework.FormRuntime.SendMail(String messageXml)
at SourceCode.Forms.Runtime.AJAXCall.ProcessRequest(HttpContext context)
 

Diagnoses

Diagnosis:
EWS URL was accessible and the Mail Protocol was configured correctly. Mail Server was not set to Default in Environmental fields on Workspace.
 

Resolution

Resolution:
SmartForms use Environmental fields and they are the first point to check when troubleshooting SmartForms issues. Setting the Mail Server to Default resolved the issue.