I'm having trouble with domain names in the sender address that have two
or more consecutive hyphen/dash characters ("-").
I'm using chkuser v2.0.8 in a qmailtoaster v1.3.13 installation.
Here's what shows up in the qmail smtp log:
2007-09-27 06:07:28.019162500 CHKUSER rejected sender: from
remote <itbe.wc09.net:unknown:184.108.40.206> rcpt <> : invalid sender
Here's the bounce message back to the sender:
571 sorry, sender address has invalid format (#5.7.1 - chkuser)
I've investigated the sender and they appear to be legitimate.
In researching this issue I have found RFC 2822 that forbids "-"
characters as the first or last character in a domain name in an email
address. I've also found RFC 3490 which forbids "-" characters in the
3rd and 4th positions (from the left) if the first two characters are
not a specific two-character code, but I can't find an RFC that forbids
multiple consecutive hyphens in other positions.
I've seen in the chkuser documentation at
that chkuser will reject if there are consecutive "-".
My question is, is it proper to reject a message simply because it has
two or more consecutive "-" characters at arbitrary locations in the
domain part? If so, can someone please point me to the relevant RFC?