No mail from testimonial

[#1]

I sent my testimonial request to my older client outside wpwork. I ask him to check mail. But he said he didn't get any mail from upwork.

[#2]

Hi Md Salamoon, 

Our team is currently looking into this for you. We'll come back here once we have more information regarding your concern. 

[#3]

Hi Md Salamoon, 

I'm coming back here to let you know that the team could not resend the email because it keeps bouncing back. They have reached out to you directly through an email to assist you further with your concern. 

[#4]

Hi Avery, 

My client mail is correct but why this is bouncing back?

[#5]

Hi Md Salamoon,

Feel free to follow up directly on your ticket and our team will assist you further. You can access your tickets on this link. Thank you.