Hi all, I don't work very much with Exim but I just solved a little problem on my web
server, running Exim, that I figured I should share with the list because I wasn't able to
find this information there originally.
I use Exim in combination with another server running MDaemon under Windows via the
'smarthost' settings. Before anyone comments about this bear in mind I am a website
developer who simply got forced into this situation and do not have the time to change
things right now...
I recently added a new IP address to the web servers (Debian Sarge) /etc/network/interfaces
file. It got added to the bottom of the list below 4 other IPs that were already there and
was then restarted. Shortly their after I started receiving these error messages back from
Exim as various websites on my server called mail() via PHP:
johnsmith@???
SMTP error from remote mail server after RCPT TO:<johnsmith@???>:
host mail.mymailserver.com [xxx.xxx.xxx.xxx]: 550 www-data@???
must check for new mail first
Searches for combinations of this error message resulted in nothing for 3 days then I
remembered that I have a special security setting on my mail server called 'POP Before
SMTP'. Meaning all clients accessing the mail server via something like Outlook or KMail
must first authenticate who they are before their email will be relayed to it's final
destination for them. Because I didn't have time to learn how to set up Exim to do an
authenticated connection to my MDaemon mail server I simply added the main IP address for
the webserver to a list of 'Trusted Hosts' on my mail server and all this has worked
perfectly for me for almost 3 years now until I added the new IP address.
What I discovered was that Exim on the web server was trying to connect to the MDaemon
server using the new IP I had just added to the bottom of my /etc/network/interfaces list
and that IP was not found in my 'Trusted Hosts' list on MDaemon so it wouldn't do the relay
anymore. I added the new IP and tried again, everything is working again.
I hope this helps someone else in the future.
Vince
