Send Outlook Mail Message: The specified string is not in the form required for a subject problem

I have problem when send email and i got error like this.


i’ve try to fix it like to convert again using convert.ToString but it doesn’t work. I’m sorry if my english not good.


Welcome to community!!

Could you please send screenshot of send outlook mail message activity
what have you written in Subject?


i just try click something at website. if the robot not find the element, get message error and write in into the subject email. the email was html. so, i got error again when i send email.