[IMail Forum] SMTP Max Connections + Imail Tunning + Postfix

[Sergio Rinc�n Jaramillo]

Hi there:   I have a question that is bothering me for about a year on.   My Imail system is   Imail V 8.13  + Declude AV + Fprot + Declude Hijack IBM Xseries 235 ( 1.5 GB RAM + 200 GB HD's + 10/100/1000 Nics) 3 x E1 Internet Direct Connection.   We are an ISP down here, an currently have like 12000 Mailboxes for primary domain and like 250 Virtual Hosts. (20 MailBoxes per Vhost).   From some big time, our server suddenly stops sendindg the emails at the queue and we have to force it to send all email through a Postfix gateway (Wich is from my perspective, the best smtp server around, the only missing or hard thing is the logging format, much easyer with Imail Syslog to catch a problem), but well thats not the big issue.   Searching around the web, newsgroups, etc, i fount this article at Ipswitchs website (http://support.ipswitch.com/kb/IM-20020315-DM02.htm) wich tells me the way to find out the current SMTP connections active at the server. Also, i found this other article (http://support.ipswitch.com/kb/IM-19980119-DD02.htm) that tells that with more than 70 connections "SMTP performance will begin to suffer, in some cases dramatically" .   This is my current response from the telnet to my server:   >telnet imail.noc-geonet.com 25   220 geo.net.co (IMail 8.13 18171-79) NT-ESMTP Server X1       As you can see, this tells me that i Have like 79 connections active, the average for this values is like 50-63 . When connections rise 60 , the telnet can take like 3-10 seconds to respond.   So the big question  is:   How come, there are other companys with like 1000 Vhosts and more email volume than us, doing to handle the concurrent connectoins with Imail?   Is it possible to increment the actual response of the server for external Email connections (Because, recently, if i send for example an email from yahoo, it can take at least 2 hours to reach our server, but if i try to send an email a second later, it gets instantly to the server ??)   Whats the best solution for a company like ours, beside using 100% Imail for the EmailService?   Have you guys tried for example having Imail only as the frontend for the customers, but having like Postfix for receiveing and sending all the emails??       Sergio Rinc�n Jaramillo    Ingeniero Telem�tica GeoNet S.A.    TEL (574) 5104701 Fax (574) 2350160 L�nea �nica de Atenci�n al Cliente 3500111 Calle 34B N� 66� 42, Medell�n, Colombia   Ya visit� nuestro sitio www.geo.net.co   Las opiniones que se expresan en este e-mail son personales y no necesariamente coinciden con las de GeoNet S.A. Este e-mail y todos los archivos transmitidos en �l, incluidas las respuestas y los reenv�os (que pueden incluir modificaciones) son confidenciales y de uso exclusivo del destinatario original, no se debe revelar ni utilizar por una persona distinta al destinatario ni copiar por medio alguno.