Not receiving email from external user

Prof. Aoyama,

I tried to send email from non-member address to our ML, but not receiving
due to TC setting. I got a daemon reply as:

<>: permission denied. Command output:
Sorry,
    only certain individuals may post to this committee. If you participate
in
    this committee and have posting privileges, but are having trouble
posting,
    please forward this error message to  (#5.7.2)
    ERROR: postqmail-local Error #77

Since we have our contact information in WD as this ML, we have two options
now:
 * Set this ML as open
   This should be done with "basic policy settings" in [1] (by TC chair?)
 * Create another ML from contact from external users
   I think we should contact to OASIS to make a request

[1] https://www.oasis-open.org/apps/org/workgroup/oslc-promcode/settings.php

Regards,
Kaz