IMAP goes down with high traffic

[mars solutions]

Hello everybody,

is there a technical limit regarding the maximum imap sessions the scalix imapd accepts at one time?
We experience a problem using SWA leading to this message:

2009-12-07 10:49:08,356 ERROR [MailServices.authenticate:559] Cannot connect to the mail server at mailgate.XXX!
The mail server on mailgate.XXX appears to be down.
javax.mail.MessagingException: Connection refused;
nested exception is:
java.net.ConnectException: Connection refused
at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:558)
at javax.mail.Service.connect(Service.java:275)

...when there's high traffic/usage on the server.

Any hints are welcome, thanks in advance.

Greets,
Seb.

[PrisonMind]

hi,

in the file : /var/opt/scalix/??/s/sys/general.cfg are some imap options!

It says:
# These tweaks limit the number and rate of IMAP connections to the
# server. The IMAP_CONNECTION_LIMIT simply restricts the total number of
# connections to the server -- note that many IMAP clients have several
# connections for each IMAP session. The IMAP_CONNRATE_LIMIT restricts
# the rate at which clients can connect to the server, in this case, at
# most ten connections per second; if clients try to connect faster
# than that, the IMAP server simply slows down the rate at which it will
# accept new connections.
IMAP_CONNECTION_LIMIT=500
IMAP_CONNRATE_LIMIT=10

after saving the setting restart scalix for it to take effect.

[mars solutions]

that's a starter. i might have thought too complicated in the first
thx.