Sending Emails using User/Sandboxed Solutions

If you've done any kind of work ​emailing using SharePoint you are probably aware of the SendEmail method available through the SharePoint object model as part of the Microsoft.SharePoint.Utilities namespace. It's very useful as it allows us to send emails with a minimum amount of effort and without having to know the SMTP settings and such like.

In user/sandboxed solutions, this method is not available so we're left in a bit of a limbo, not knowing how to achieve it as there's nothing else available in the object model that achieves the same thing. Let's say we have a custom "Contact Us" webpart which sends someone an email with the contact information: how can you achieve the same thing?

We could use the System.Net.Mail methods available to us, but is it reasonable to expect a content author to supply the webpart with the appropriate SMTP settings? Why is that an issue? Well, these settings can be accessed programmatically using the object model which would resolve this minor difficulty, but they are not available in a sandbox. They exist at Web Application level and are therefore off limits.

Fortunately, there is another way, and that is through using SharePoint Designer workflow. You can trigger a workflow to run programmatically and also supply information to the workflow and set the initiation values. Here's the code to start a workflow:

/// <summary>
/// Method to handle starting the appropriate Workflow as specified by the Site Collection Workflow Name property
/// </summary>
private void StartWorkflow()
{
SPWorkflowAssociation wfa = SPContext.Current.Web.WorkflowAssociations.GetAssociationByName(this.SiteCollectionWorkflowName, CultureInfo.InvariantCulture);
wfa.AssociationData = this.GetWorkflowInitiationData();
SPContext.Current.Site.WorkflowManager.StartWorkflow(null, wfa, this.GetWorkflowInitiationData(), SPWorkflowRunOptions.Asynchronous);
}

/// <summary>
/// Method to construct the Workflow Initiation/Association Data
/// </summary>
/// <returns>A string containing the XML schema and values necessary for the Association Data</returns>
private String GetWorkflowInitiationData()
{
String schema = "<dfs:myFields xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" " +
"xmlns:dms=\"http://schemas.microsoft.com/office/2009/documentManagement/types\" " +
"xmlns:dfs=\"http://schemas.microsoft.com/office/infopath/2003/dataFormSolution\" " +
"xmlns:q=\"http://schemas.microsoft.com/office/infopath/2009/WSSList/queryFields\" " +
"xmlns:d=\"http://schemas.microsoft.com/office/infopath/2009/WSSList/dataFields\" " +
"xmlns:ma=\"http://schemas.microsoft.com/office/2009/metadata/properties/metaAttributes\" " +
"xmlns:pc=\"http://schemas.microsoft.com/office/infopath/2007/PartnerControls\" " +
"xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">" +
"<dfs:queryFields /><dfs:dataFields><d:SharePointListItem_RW>{0}</d:SharePointListItem_RW>" +
"</dfs:dataFields></dfs:myFields>";


StringBuilder sb = new StringBuilder();
sb.AppendFormat("<d:EmailTo>{0}</d:EmailTo>", this.SendToEmailAddress);
sb.AppendFormat("<d:EmailSubject>{0}</d:EmailSubject>", this._subject.Text);
sb.AppendFormat("<d:EmailText>{0}</d:EmailText>", this._comments.Text);
sb.AppendFormat("<d:AutoResponseTo>{0}</d:AutoResponseTo>", this._email.Text);
sb.AppendFormat("<d:AutoResponseSubject>{0}</d:AutoResponseSubject>", this.AutoResponseSubject);
sb.AppendFormat("<d:AutoResponseText>{0}</d:AutoResponseText>", this.AutoResponseText);
return String.Format(schema, sb.ToString());
}

The StartWorkflow method is where the workflow starts and the GetWorkflowInitiationData is where the XML erquired to set the initiation properties are set up. From what I've seen, the XML stays pretty-much the same with properties being set using the "dataFields" namespace "d:". The property names are workflow initiation properties I set up in my workflow.  The SiteCollectionWorkflowName used in the StartWorkflow method is a property of the webpart which could be hidden away.