>>but Imail, like any mail machine, chokes dominantly with disk congestion
Sure. But Imail gags on a basic amount. The Queue Mangler on 8.0 had us running back to 7.15, while a basic BSD relay box on a fraction of the hardware would serve the gateway functionality with ease. Of course, YMMV. >>A gateway that doesn't reject anything is hardly worth the effort. There is a little more to gateways than that, I think. There is a reason email bound for microsoft.com hits 3 layers of gateways before arriving at one of the Exchange Servers. Our biggest concern is security. I want the outermost relay to be basic and secure; however, in the event of its compromise, there is little or nothing there. No user database. No access to an internal network. Nothing. Anti-spam and anti-virus are second, but also a great benefit to keep from arriving on a mailbox server. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Len Conrad Sent: Thursday, November 20, 2003 12:57 PM To: [EMAIL PROTECTED] Subject: Re: [IMail Forum] telnet localhost 25 connection failed >With 2 gateways, that's 250K per server Why two gateways? there is only Imail and one MX gateway. > -- half the load, minus web messaging and such. Plus, a gateway can > tolerate higher CPU usage (users won't be connecting via POP3, so they > won't notice the CPU usage). Also, with 2 gateways, if IMail chokes > on one (receiving more E-mail than it can handle), the other will > automatically be used. but Imail, like any mail machine, chokes dominantly with disk congestion, so 500k msgs received by the gateway, queued, logged, unqueued and SMTP-sent to Imail is about the same load as Imail itself receiving, logging queuing, unqueueing, logging, writing to perhaps large mbx files on fragged disks. So where's the benefit of a gateway? (for the lurkers) 1. a gateway that rejects the usual 70+ % of inbound that is spam, that's 70% less on Imail, the biggest contribution by the gateway. A gateway that doesn't reject anything is hardly worth the effort. 2. the SMTP send/receive between Imail and the gateway excludes DNS query delays and SMTP-over-internet session delays, so Imail's send/receive sessions are much shorter, occupying less memory. A benefit, but not nearly as large as 1. 3. Imail outbound queue is always 0 since it drops outbound mail on the gateway in 1 or 2 seconds. Of course, this situation arises only if IMail doesn't have internal problems sending the outbound queue, which happens too often, but less so with a gateway. 4. if Imail can manage to send its outbound queue to the gateway, then any of it that is undeliverable by the gateway and gets deferred to the gateway's queue doesn't occupy Imail queue, Imail retrying, relogging, etc, etc. Len To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
