Use below commands SharePoint Management Shell in order to verify that SharePoint Outgoing mail works fine. Make sure you have added Outgoing Mail Server and Sending mail account under Outgoing email setting in Central Admin.
01. $site = New-Object Microsoft.SharePoint.SpSite(http://webSite)
02. $web = $site.OpenWeb()
03. $sent = [Microsoft.Sharepoint.Utilities.SpUtility]::SendEmail($web,0,0,”firstname.lastname@example.org”,”Test mail subject”,”test mail body”)
If the result from 04 is true. Outgoing E-mail is configured and working perfectly.