Notification email not getting sent.. says No developers have been configured

1) I have gmail settings configured correctly in jetty.xml
2) I have 3 other users (roles ) created for the project as developers
3) I have configured project group and project notifiers
4) I even get an email on a build when I specify email as my own admin account email address
5) But when I specify other developer's email address or group email address, mail does not get sent. I see this message in the log file
WARN "No developers have been configured notifcation email will not be sent"
Although I have that developer's email address and group email address configured as project developers.