Cannot input mail-address in Quick Add of Membership

Dear FTH Support,
I am IT support for Kamakura Toastmasters club (2933).
I tried to add one following member into the Membership by Quick Add, but failed due to mail adress.
  Name: Haruko Ohki
  Mail-address:  sunshine-06@ams.odn.ne.jp
When I input this mail-address in Quick Add, then this mail address turned to Red color.
I assume this  error was caused by mail address.
However, this mail address  can be used every day.
I cannot understand why this mail addreess could not be used in ordet to add this member.
Looking forward to your prompt reply to solve this problem.
Best regards,
Satoru Yamasaki

 

 

That email address already exists in former members for your club.

Dear FTH support,
Thanks so much for your support and reply.
This problem was solved by your suggested solution.
Best regards,
Satoru Yamasaki.