Comment 1 for bug 1010259

Was the list's preferred_language set to Greek when you set the nonmember_rejection_notice, and when the rejection was sent?

If the list's preferred_language is English and you want to include non-ascii characters in nonmember_rejection_notice or any other messages, you need to change Mailman's character set for English from us-ascii to utf-8 by putting

add_language('en', 'English (USA)', 'utf-8', 'ltr')

in mm_cfg.py