Hello Oliver, On Tue, December 16, 2008 11:15, Oliver Howe wrote: > > > A lot of my users are complaining that they are receiving bounce back > emails of messages that they did not send. Each message contains some > kind of spam text at the bottom. > > For example, from the headers below the message came from > [212.40.112.118] (helo=pool-01077.externet.hu) which has nothing to do > with my domain (postmaster.co.uk). > > So I'm thinking I could check the envelope-from on my mailservers and > reject if it is for a local user who is not coming from one of my > mailservers (so then they can still send to themselves if they want to). > Has anyone else had this problem? Is there a better solution? >
Yes, there is a better solution. Some NDR may come from servers which are not yours, for example, multistage relays. So you probably don't want to block legitimate NDRs. There is a solution to this, which is signing return path. This can be done either with exim PRVS feature (look in the docs for prvs). Or with custom signatures like described here: http://slett.net/spam-filtering-for-mx/collateral.html#signedsender -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
