Urgent help due to e-mail address not recognized correctly

Dear Support,
I request urgent help on the following incident.
Incident: FreeToastHost refused the following e-mail address by showing the Subject.Subject: [FreeToastHost] Message Not Delivered: Re: Summer Live
by showing the following message
 This email address is being protected from spambots. You need JavaScript enabled to view it. appears to be an invalid or non-working recipient email address. (One Advertised SMTP server permanently refused mail.)

However, the above e-mail address "amapea914@icloud.com" is available and we can use this e-mail address without FTH environment.
Looking forward to your confirmation and providing the causes and solutions.

Best regards,
Satoru Yamasaki (Rock Music TMC FTH Administrator) 

 

I can see This email address is being protected from spambots. You need JavaScript enabled to view it. accepting email from FTH.

I will need the full internet email header to see what the issue is.

From our test it is a user problem

 

Dear Brian,
Thanks so much for your prompt reply.
As a result of gurther check, we solved this problem due to a lack of receiving tray quantity.
Best regards,
Satoru Yamasaki