Cannot connect to SMTP host - Event 6857 (SharePoint 2010 Products)


Applies to: SharePoint Server 2010, SharePoint Foundation 2010

Alert Name:   Cannot connect to SMTP host

Event ID:   6857

Summary:   Microsoft SharePoint Foundation 2010 sends alerts and other administration messages by using an SMTP mail server. You can specify which SMTP server to use to send the alerts, and you can set the e-mail address to use for sending alerts and receiving replies for all sites, by using the Outgoing E-Mail Settings page on the SharePoint Central Administration Web site.

Symptoms:   The following symptoms might appear:

  • Cannot send e-mail by using SPUtility.SendEmail

  • Cannot send e-mail messages, including alert e-mail, confirmation e-mail, invitation e-mail, e-mail about exceeding quota

  • This event appears in the event log: Event ID: 6857 Description: Cannot resolve name of SMTP host <host id>.

Cause:   One or more of the following might be the cause:

  • Microsoft SharePoint Foundation cannot connect to the SMTP host.

  • SharePoint Foundation cannot resolve name of the outbound SMTP server.


You must be a member of the Farm Administrators SharePoint group to perform the following actions.

Resolution:   Start and configure the SMTP service

  1. In Internet Information Services (IIS) 6.0 Manager, connect to the SMTP server.

  2. Expand the server node and look for the SMTP virtual server that is used by SharePoint Foundation.

  3. Right-click the correct virtual server and click Start.

  4. To configure the virtual server, open the virtual server's properties.

  5. On the Delivery tab, click Outbound Security.

  6. In the Outbound Security dialog box, select either Anonymous access or Integrated Windows Authentication. If you select Integrated Windows authentication, make sure that the SharePoint Foundation Central Administration application pool account is authenticated on the SMTP server by selecting the Account and Password check boxes.

Resolution:   Configure outgoing e-mail settings in Central Administration

  1. On the Central Administration page, click System Settings and in the E-Mail section click Configure Outgoing E-Mail Settings.

  2. On the Outgoing E-Mail Settings page, in the Mail Settings section, type the correct SMTP server in the Outbound SMTP server text box.