Trying to respond to a post by replying to launchpad emails bounces with a nasty jive message below :

This is the mail system at host mx1-in2.phx1.jivehosted.com.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own text from the attached returned message.

The mail system

: host 10.172.67.202[10.172.67.202] said: 553 address unknown. (in reply to RCPT TO command)

Could someone look into it, please?