I have no idea when or why this started happening for me but I started getting Unrouteable address appearing for any external address.
I’m a huge fan of Debian but there are some things that really piss me off. One is the way they have completely screwed the exim4 configuration. Exim4, if you are not an administrator or mail guru is not the simplest thing in the world to configure, it’s config file is fairly involved and you can do anything in it. Add DEBCONF variables to this and you have a complete nightmare configuration.I spent two days tracking this error down to the following:
DCconfig_internet=1
That was all I had to add to /etc/exim4/exim4.conf.template
Why this changed I have no idea. The setting I am using in /etc/exim4/update-exim4.conf.conf is
dc_eximconfig_configtype=’internet’
I really cannot make head nor tail out of this at all. I sometimes wish I had started learning Postfix instead of Exim but part of me thinks that it’s not Exim but rather the way it has been packaged up thats compicated.
Not having used Exim myself, I can’t say for sure, but I expect that its default behaviour is to only deliver mail to local mailboxes and/or domains. The DCconfig_internet=1 setting allows it to communicate with external SMTP servers.