Harald Strack put forth on 9/27/2010 3:59 AM:
Hi,
I set mail_max_userip_connections in our IMAP configuration to
mail_max_userip_connections = 10
to allow users 10 parallel connections. It seems that this also limits the amount of parallel connections from one IP but different users?!
Our users mostly accessing the IMAP server by a webmailer or proxies. Thus, all users (>10000) come from only 5 different IP. However, I got a lot of complaints about denied connections after setting mail_max_userip_connections = 10.
Am I right with the meaning of this parameter?
More importantly, what were you attempting to accomplish by setting this? What problem were you expecting it to solve?
Webmail servers typically don't hold an IMAP connection open for more than a few seconds so this setting does nothing in a webmail only environment.
Proxies on the other hand, such as imapproxy, will hold concurrent connections open for quite a while. Enabling this setting with upstream imap proxies is a bad idea, as you've discovered.
Again, what specific problem are you trying to solve?
-- Stan