Hi Mihamina, > [mihamina at recette53 ~]$ rpm -aq | grep exim > exim-4.72-4.el6.x86_64 > > [mihamina at recette53 ~]$ telnet localhost 25 > Trying ::1... > Connected to localhost. > Escape character is '^]'. > 220 recette53.ideoneov.com ESMTP Exim 4.72 Mon, 11 Mar 2013 10:09:27 +0100 > HELO mihamina > 250 recette53.ideoneov.com Hello localhost [::1] > MAIL from: <mrakotom at free.fr> > 250 OK > RCPT to: <mihamina at rktmb.org> > 550 relay not permitted > > > mihamina at recette53 ~]$ telnet 127.0.0.1 25 > Trying 127.0.0.1... > Connected to 127.0.0.1. > Escape character is '^]'. > 220 recette53.ideoneov.com ESMTP Exim 4.72 Mon, 11 Mar 2013 10:10:26 +0100 > HELO mihamina > 250 recette53.ideoneov.com Hello localhost [127.0.0.1] > MAIL from: <mrakotom at free.fr> > 250 OK > RCPT to: <mihamina at rktmb.org> > 250 Accepted > DATA > 354 Enter message, ending with "." on a line by itself > From: <mrakotom at free.fr> > To: <mihamina at rktmb.org> > Subject: Haftra Andrana I'm not a specialist on EXIM, but obviously your system resolves 'localhost' to the IPv6 address ::1. Probably you have allowed EXIM to relay for 127.0.0.1/8, but not for ::1, so it will allow relay access on IPv4 localhost, but not on IPv6 localhost. Cheers, Peter.