Failed to send your message. Please try later or contact the administrator by another method (contact form 7 )

i am new to wordpress . i am facing problem with contact us form. where will be the setting like SMTP or php mail for contact us form (i am using contact form 7 plugin . also i installed wp-smtp. ) i am getting the following error message

Failed to send your message. Please try later or contact the administrator by another method. with red border.

please help me out to solve this issue.