alert for ssl certification

Hi All,

our company has new request get alert for ssl certification expire before 15 days. i have gone through the below url

https://support.f5.com/csp/article/K15288

but got error unable to relay. then i have added host ip address is mailhub server then got error " 530 5.7.1 Client was not authenticated"

i can telent with port 25 and 587 from F5. Kindly help on this.