[Dovecot] LTMP Proxy fails when backend server connection refused

[Jack Bates]

Version: 2.1.9

Connecting directly to the proxy server on the LMTP port, issue lhlo, 
mail from, rcpt to, data. After the . closing of data, it just hangs 
there. The logs on the proxy server show:

Sep 27 19:55:12 proxy1 dovecot: lmtp(9398): Connect from 69.8.2.71
Sep 27 19:55:24 proxy1 dovecot: lmtp(9398): Error: lmtp client: 
connect(lmtp, 7025) failed: Connection refused

root      9398  1102  0 19:53 ?        00:00:00 dovecot/lmtp

The proxy server is hard coded (not director in this case). I 
purposefully shut it down to see how the system would handle failures. 
Unfortunately, it appears that the process just hangs there. For fun, I 
tried a separate protocol lmtp option in the config to try 
proxy_timeout. It made no difference. Missing some error handling?

protocol lmtp {
         passdb {
                 driver = static
                 args = proxy=y host=%s nopassword=y proxy_timeout=120
         }
}


Jack