Searching HAProxy Enterprise 1.8r1
Configuring IMAP4
IMAP4 is a mail protocol that allows users to be disconnected from the main messaging system and still be able to process mail. Users can store messages on a local machine or on a server.
IMAP4 protocol can work over two types of connection: in clear (called IMAP, default port 143) or over TLS (called IMAPs, default port 993). Hence, you can choose a variety of deployment types:
TCP forward on IMAP (TCP/143) only
TCP forward on IMAPs (TCP/993) only
SSL offload on IMAPs (TCP/993) only
TCP forward on both IMAP (TCP/143) and IMAPs (TCP/993)
TCP forward on IMAP (TCP/143) and SSL offload on IMAPs (TCP/993)
Note
SSL offload means that HAProxy terminates the SSL/TLS connection and deciphers the traffic. It is not compatible with STARTTLS where the connection starts as clear and then switches to TLS. To be compatible with STARTTLS, use the TCP forward configuration.
The configuration template below introduces HAProxy configuration for MS Exchange 2010 IMAP service in TCP forward on both IMAP (TCP/143) and IMAPs (TCP/993) layouts.
You may have to modify these parameters to suit your environment:
bind
-
The listening IP (usually an IP address configured over VRRP)
server
-
The server name and IP addresses
Note
You can use the default XCHANGE2010_TCP
section for other Exchange 2010 TCP based services. There is no need to duplicate it.
defaults XCHANGE2010_TCP
mode tcp
log global
option tcplog
balance leastconn
option dontlognull
option redispatch
option contstats
option socket-stats
timeout server 600s
timeout client 600s
timeout connect 5s
timeout queue 60s
retries 3
default-server inter 15s rise 2 fall 2
backlog 10000
frontend ft_xchange2010_imap
bind 10.0.0.3:143 name IMAP tcp-ut 30s
bind 10.0.0.3:993 name IMAPs tcp-ut 30s
default_backend bk_xchange2010_imap
backend bk_xchange2010_imap
option tcp-check
tcp-check connect port 143
tcp-check expect string * OK
tcp-check connect port 993 ssl
tcp-check expect string * OK
default-server on-marked-down shutdown-sessions
server CAS1 10.0.0.15 check
server CAS2 10.0.0.16 check