On 10/24/2011 9:30 PM, Poh Yong Hwang wrote: > Hi all, > > New to this mailing list here. > > I have a requirement to setup a mail system for 200,000 users and it needs > to be Postfix for SMTP and dovecot 2 for IMAP. > > May I know what is the best setup for such an implementation? Can postfix be > clustered?
Clustering of SMTP servers is accomplished by setting equal MX priority in DNS for a given domain's MX hosts. For example: ~$ dig mx ibm.com ... ibm.com. 3600 IN MX 10 e1.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e3.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e32.co.us.ibm.com. ibm.com. 3600 IN MX 10 e2.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e4.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e5.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e6.ny.us.ibm.com. ibm.com. 3600 IN MX 10 e33.co.us.ibm.com. ibm.com. 3600 IN MX 10 e35.co.us.ibm.com. ibm.com. 3600 IN MX 10 e31.co.us.ibm.com. ibm.com. 3600 IN MX 10 e34.co.us.ibm.com. This is a cluster of 10 inbound mail servers, though I'm not sure if they're running Postfix. Wietse maybe can tell us as he works for IBM. The banner is ambiguous, possibly security through obscurity at play? As to the Deovecot configuration for 200K mailboxes you should ask on the Dovecot mailing list. -- Stan