Need sendmail to split single envelope into multiple To: addresses
Having a small sendmail issue I've been trying to figure out...
Our system uses email to send fairly time-sensitive status messages between programs running on various servers on a WAN. Each email message is sent to two addresses (different servers). The problem occurs when one of the destination mail servers is off the network. I think because it's trying to send one email to two addresses, sendmail attempts delivery to the first address, then to the second address (i.e., serially). When this happens, it hangs for two connect timeout (CONNECT_TO) periods trying to connect to the offline destination, then after the timeout, it then delivers to the other destination. I'm trying to figure out how to work around that connection delay so it doesn't delay delivery to the other destination.
I'm working with the network guys to enable the right ICMP messages that signal when a network is unavailable, but I would also like to try having sendmail split the emails into two envelopes, then use parallel, independent connections for delivery.
After days of reading through the docs (O'Rielly Sendmail book + sendmail docs) I think one way to do this is to use multiple mail queues, but I can't decipher exactly how to do that from the docs.
There might be other, more elegant ways to do the same thing, but again, trying to decipher the docs has my head swimming. (This is my first experience with sendmail.)
Can anyone offer any suggestions? I sure would appreciate any help!