This error appears because you have not filled the below setting:
<setting name="Analytics.EMailFromAddress" value="" />
in Sitecore.Analytics.config.
Also, check if in the web.config file the "MailServer" setting is filled in with an address of your SMTP server as well as the "MailServerUserName", "MailServerPassword" and "MailServerPort".
In the ProcessSubscriptions processor you have next code that use Analytics.EMailFromAddress setting :
public class ProcessSubscriptions : CommitSessionProcessor
{
public override void Process(CommitSessionPipelineArgs args)
{
try
{
Assert.IsNotNull(args.Session, "Tracker.Current.Session is not initialized");
ISmtpClient smtpClient = (Factory.CreateObject("emailprovider", false) as ISmtpClient) ?? new SmtpClientWrapper();
Session session = args.Session;
CurrentInteraction interaction = session.Interaction;
Assert.IsNotNull(interaction, "visit");
interaction.UpdateLocationReference();
if (!interaction.LocationId.HasValue)
{
Log.Debug("[Analytics]: The CommitSession pipeline, ProcessSubscriptions - Location id IS NUll, the processing is terminated", this);
}
else
{
LocationData locationData = Tracker.Dictionaries.Locations.Get(interaction.LocationId.Value, LookupStrategy.Default);
if (locationData == null || !locationData.Subscriptions.Any<string>())
{
Log.Debug("[Analytics]: The CommitSession pipeline, ProcessSubscriptions is skipped - there is no subscriptions for location id: " + interaction.LocationId.Value, this);
}
else
{
HtmlTextWriter htmlTextWriter = new HtmlTextWriter(new System.IO.StringWriter());
htmlTextWriter.Write("<html>");
htmlTextWriter.Write("<head></head>");
htmlTextWriter.Write("<body>");
ProcessSubscriptions.RenderSummary(htmlTextWriter, session);
ProcessSubscriptions.RenderSessionTrail(htmlTextWriter, interaction);
ProcessSubscriptions.RenderSessionLink(htmlTextWriter, interaction);
ProcessSubscriptions.RenderUnsubscribeLink(htmlTextWriter, interaction);
htmlTextWriter.Write("</body>");
htmlTextWriter.Write("</html>");
MailAddress from = new MailAddress(AnalyticsSettings.EmailFromAddress);
MailMessage mailMessage = new MailMessage
{
From = from,
Subject = string.Concat(new object[]
{
"[Sitecore Analytics] ",
interaction.GeoData.BusinessName,
" visited the site at ",
DateUtil.ToServerTime(interaction.StartDateTime),
"."
}),
Body = htmlTextWriter.InnerWriter.ToString(),
BodyEncoding = System.Text.Encoding.UTF8,
IsBodyHtml = true
};
foreach (string current in locationData.Subscriptions)
{
mailMessage.Bcc.Add(current);
}
try
{
smtpClient.Send(mailMessage);
}
catch (System.Exception exception)
{
Log.Error("Failed to send subscription notification", exception, typeof(ProcessSubscriptions));
}
Log.Info("SubscriptionTask done.", this);
}
}
}
catch (System.Exception exception2)
{
Log.Error("Cannot process 'ProcessSubscriptions' processor because of internal error", exception2, this);
}
}
