[imapproxy] ImapProxy stops accepting connections

[Nuno Miguel Pinto Lopes]

I have been using ImapProxy for a small environment that doesn't have more than 200 simultaneous users and it's been working fine. So I thought it was time to move it to my large instalation that peaks at 1800 users. That's when I started having problems. The server hanged after som time.
So I adapted the expect test so that it opened connections for 2000 users one after another.
The first problem that I found out was with the limit number of open files. The error was explicit (parent_conversate(): Couldn't create ipc pipe Too many open files) so I raised the number of open files with ulimit.
Now what I get is a server that handles the first 1019 users but then stops accepting connections. The proxy keeps sending NOOPs to the Imap server and the Imap Server keeps accepting connections. 
I couldn't find anything in the proxy code that would point to an hard limit in the number of connections, but I couldn't find any such limit in my configuration.

I am running ImapProxy in a 2.4.16 Linux kernel. Could anyone help me with this problem?

Thanks,
-- 
Nuno Lopes
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