On Fri, 03 Jul 2015 07:05:43 +0200 Urban Loesch wrote:
Hi,
Am 03.07.2015 um 05:14 schrieb Christian Balzer:
- Here is where the fun starts. Each IMAP session that gets proxied to the real mailbox server needs a port for the outgoing connection. So to support 2 million sessions we need 40 IP addresses here. Ouch. And from a brief test having multiple IP addresses per server won't help either (Dovecot unsurprisingly picks the main IP when establishing a proxy session to the real mailbox), at least not with just one default GW.
If I remeber correctly there is a config option in dovecot 2.x where you can set the ip addresses which dovecot should use for outgoing proxy connections. Sorry, but I can't remeber the option.
Looking at the documentation on the Wiki I was going to say "That won't help", as it says address. http://wiki2.dovecot.org/PasswordDatabase/ExtraFields/Proxy
But since that page is rather terse, I looked up the changelog and found that it indeed was added for use cases like mine: http://www.dovecot.org/list/dovecot-cvs/2014-June/024574.html
Unfortunately the latest dovecot version in Debian is 2.2.13...
Additionally this still leaves the actual mailbox servers, which in my case will need to be able to handle more than 50k sessions as well.
Thanks for the info,
Christian
Christian Balzer Network/Systems Engineer
chibi@gol.com Global OnLine Japan/Fusion Communications
http://www.gol.com/