Issue email in plesk is receive only not send and display (26) DNS lookup failure

[eng_nermeen]

when send email from email plesk system dont send email when I open log mail system display this error
virtualserver01 spf[20290]: Error code: (26) DNS lookup failure

 

[IgorG]

Cannot send messages to remote servers: DNS Lookup failure: Domain mail.example.com does not exist

Applicable to: Plesk for Windows Symptoms Messages cannot be sent to remote mail servers, a bounce message is returned instead: CONFIG_TEXT: MailEnable: Message could not be delivered to some ...

support.plesk.com

 

[eng_nermeen]

RDP is not working when i install is there another way?