IMAP-Server Maximum number of connections

[Thomas_Krcal]

Hello

My Customers and I have Problems connecting to IMAP-Server.
By moving through IMAP Folders I get the Massage
"Unable to connect to your IMAP server. You may have exceeded the maximum number of connections to this server"

Of course !!
I know this Article:
http://kb.odin.com/en/113841
an all the other related to this issue.

My current Values are:
MAXPERIP=60
MAXDAEMONS=120
and I still get this error.

Also very strange is:
when I type
sudo netstat -tupn | grep "194.XXX.XXX.71" (194.XXX.XXX.71 -> is my client IP)

tcp 0 0 217.XX.XX.156:587 194.XXX.XXX.71:55495 ESTABLISHED 65351/smtpd
tcp 0 0 217.XXX.XXX.156:587 194.XXX.XXX.71:55496 ESTABLISHED 65354/smtpd
tcp 0 0 217.XXX.XXX.156:80 194.XXX.XXX.71:55656 TIME_WAIT -
tcp 0 48 217.XXX.XXX.156:22 194.XXX.XXX.71:50493 ESTABLISHED 58759/1
tcp 0 0 217.XXX.XXX.156:22 194.XXX.XXX.71:54822 ESTABLISHED 64385/sshd: root@no
tcp6 0 0 217.XXX.XXX.156:993 194.XXX.XXX.71:55008 ESTABLISHED 65086/couriertls
tcp6 0 0 217.XXX.XXX.156:143 194.XXX.XXX.71:55498 ESTABLISHED 65356/imapd
tcp6 0 0 217.XXX.XXX.156:143 194.XXX.XXX.71:55504 ESTABLISHED 65373/imapd
tcp6 0 0 217.XXX.XXX.156:993 194.XXX.XXX.71:55007 ESTABLISHED 65084/couriertls
tcp6 0 0 217.XXX.XXX.156:993 194.XXX.XXX.71:55009 ESTABLISHED 65088/couriertls
tcp6 0 0 217.XXX.XXX.156:143 194.XXX.XXX.71:55018 ESTABLISHED 65132/couriertls
tcp6 0 0 217.XXX.XXX.156:143 194.XXX.XXX.71:55014 ESTABLISHED 65093/couriertls
tcp6 0 0 217.XXX.XXX.156:993 194.XXX.XXX.71:55006 ESTABLISHED 65082/couriertls

This are far not 60 connections.

Another question by the way.
What exactry does MAXDAEMONS mean ?
Are this the number of IMAP-Connections on the Server at all ? ... (for all Mail Adresses ?)

Thank you
Tom,...

 

[abdi]

Hello Tom,

Tweak those numbers based on your client base; if 50 clients are connecting to the email server from behind the same firewall then MAXPERIP could need to go as high as 250 (50 clients x 5 cached mailbox connections). Add email clients of people working from home and MAXDAEMONS could go as high as 300 or 400!

Obviously, the connection limits are to prevent the server from using too much memory and/or CPU resources on the machine. Tweak the numbers based on the server hosted services it has and it's available memory resources. If you are still receiving this error after making these changes, you might want to consider other ways to reduce usage or possibly upgrading your server / resources.

 

[Thomas_Krcal]

Im Sorry but your answer did not solve my problem at all.

Lets repeat the facts:
My current Values are:
MAXPERIP=60
MAXDAEMONS=120

netstat -tupn | grep "194.XXX.XXX.71" (194.XXX.XXX.71 -> is my client IP)

Shows, my Ip only only 8 or 9 times

So why I got this error when I am far below MAXPERIP and MAXDAEMONS

Also my CPU and MEMORY resources cant not be too little.
I have a strong server and installed only 3 Customers for testing
top
CPU ist 99,7% id; swap is used 0k; Mem is free 12638876k
So please

 

[Thomas_Krcal]

For MAXDAEMONS again

I can imagine what it means,
but my question was:
Does it means for the server at all -- or per IP

Thank you

 

[abdi]

MAXDAEMONS is the total number of IMAP connections the server would accept.

 

[Thomas_Krcal]

And have you got an idea why i got this message in client.
I am not in the near of
MAXPERIP=60
also not
MAXDAEMONS=120

 

[abdi]

What email client are you using with which you are seeing this error?
It seems to be a common problem with Thunderbird.

http://kb.mozillazine.org/IMAP:_advanced_account_configuration
http://forums.mozillazine.org/viewtopic.php?f=39&t=1385655

 

[Thomas_Krcal]

I am using Thunderbird.
One of my customers telling me to get this Error on Iphone and Apple Mail Client.

 

[Thomas_Krcal]

I play around again with these values
MAXPERIP
MAXDAEMONS

So as I understood,
MAXDAEMONS should not be smaller like the Value of MAXPERIP * (Numbers of installed emails on the Server)

Because I did not get my Errormassage in the client because of MAXPERIP .
...I did get it because of MAXDAEMONS.

...the client try to get MAXPERIP connections but because of other connected eMails there is no deamon free because of MAXDAEMONS.
Is my assume correct ?

thank you for your patience.

 

[abdi]

Yes, that is correct. You could have a thousand IMAP connections from different IPs.