Zimbra server is very slow and often goes unavailable

Here is what I get in activity viewer ( i replaced hostname with ??? ) :

13:32:10 S: * 0 EXISTS
12:57:13 Clearing connection to mail.???.com
12:57:13 Clearing connection to mail.???.com
12:57:13 Trying to connect to mail.???.com on port 993
12:57:13 Successful connection on socket 68.
12:57:13 Initiating secure connection...
12:57:14 Setup of secure connection complete (TLSv1).
12:57:14  Cipher: DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
12:57:14 Error: Error while waiting on read or write (Invalid argument).
  descriptor: 68, break_read_pipe: 71, ndfs: 71, wait_on_read: 1, wait_on_write: 0, timeout: 4294967272

12:57:14 S: 
12:57:14 Clearing connection to mail.???.com
12:57:14 Trying to connect to mail.???.com on port 143

...and I also now noticed gmail does have the same issue, just "worse":

12:59:15 Clearing connection to imap.gmail.com
12:59:15 Clearing connection to imap.gmail.com
12:59:15 Trying to connect to imap.gmail.com on port 993
12:59:15 Successful connection on socket 82.
12:59:15 Initiating secure connection...
12:59:16 Setup of secure connection complete (TLSv1).
12:59:16  Cipher: RC4-SHA                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=SHA1
12:59:16 S: * OK Gimap ready for requests from 209.132.186.32 ew9mb8323007wid
12:59:16 C: A0 CAPABILITY
12:59:16 Error: Error while waiting on read or write (Invalid argument).
  descriptor: 82, break_read_pipe: 74, ndfs: 82, wait_on_read: 1, wait_on_write: 0, timeout: 4294967288

12:59:16 S: 
12:59:16 Error code: 2
12:59:16 Failed action. Reset observed read/write timeouts: 2147483644/12
12:59:16 Clearing connection to imap.gmail.com
12:59:16 Clearing connection to imap.gmail.com
12:59:16 Trying to connect to imap.gmail.com on port 993
12:59:16 Successful connection on socket 82.
12:59:16 Initiating secure connection...
12:59:17 Setup of secure connection complete (TLSv1).
12:59:17  Cipher: RC4-SHA                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=SHA1
12:59:17 S: * OK Gimap ready for requests from 209.132.186.32 t4mb22965559wep
12:59:17 C: A0 CAPABILITY
12:59:17 Error: Error while waiting on read or write (Invalid argument).
  descriptor: 82, break_read_pipe: 74, ndfs: 82, wait_on_read: 1, wait_on_write: 0, timeout: 4294967288

12:59:17 S: 
12:59:17 Error code: 2
12:59:17 Failed action. Reset observed read/write timeouts: 2147483644/12
12:59:17 Clearing connection to imap.gmail.com
12:59:17 Clearing connection to imap.gmail.com
12:59:17 Trying to connect to imap.gmail.com on port 993
12:59:17 Successful connection on socket 82.
12:59:17 Initiating secure connection...
12:59:17 Setup of secure connection complete (TLSv1).
12:59:17  Cipher: RC4-SHA                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=SHA1
12:59:17 S: * OK Gimap ready for requests from 209.132.186.32 w44mb22790165wef
12:59:17 C: A0 CAPABILITY
12:59:17 Error: Error while waiting on read or write (Invalid argument).
  descriptor: 82, break_read_pipe: 74, ndfs: 82, wait_on_read: 1, wait_on_write: 0, timeout: 4294967288

12:59:17 S: 
12:59:17 Error code: 2
12:59:17 Failed action. Reset observed read/write timeouts: 2147483644/12
12:59:17 Clearing connection to imap.gmail.com
12:59:17 Clearing connection to imap.gmail.com
12:59:17 Trying to connect to imap.gmail.com on port 993
12:59:17 Successful connection on socket 82.
12:59:17 Initiating secure connection...
12:59:18 Setup of secure connection complete (TLSv1).
12:59:18  Cipher: RC4-SHA                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=SHA1
12:59:18 S: * OK Gimap ready for requests from 209.132.186.32 fw7mb8240482wic
12:59:18 C: A0 CAPABILITY
12:59:18 Error: Error while waiting on read or write (Invalid argument).
  descriptor: 82, break_read_pipe: 74, ndfs: 82, wait_on_read: 1, wait_on_write: 0, timeout: 4294967288

12:59:18 S: 
12:59:18 Error code: 2
12:59:18 Failed action. Reset observed read/write timeouts: 2147483644/12
12:59:18 Error: Failed multiple retries (4). Final error code was 2.

Keep the Activity Viewer open, update to the latest test version, and when you see this behavior then use “Help ▸ Send Server Logs...” and I'll get all available server communication.

(I thought this problem was fixed, but apparently I was wrong.)

Updated to latest version - now it seems to "just work".

I'll keep an eye out when/if it shows up again.

gmail went unavailable - sent you the logs.

Thanks, it was exactly the kind of output I needed. The problem is a bit embarrassing and found here:

22:09:23 S: * 16054 FETCH (UID 16055 MODSEQ (5712506))  
22:09:19 Waited 4294967292 seconds on read.  
22:09:19 S: * 16055 FETCH (UID 16056 MODSEQ (5712521))

Notice the time stamps. Your computer corrects time 4 seconds backwards and this is interpreted by MailMate as waiting a very long time before successfully reading more data. (MailMate ends up using this, heuristically, to be too patient when reading data later on.)

A new test version should be available within a few minutes.

Installing ;)

btw. you think this bug is the same for both gmail and zimbra case ?

Yes, the huge timeout value seen in the Zimbra output in your first comment to this ticket indicates that it is the same issue.