Error 5.3.4 Message size exceeds fixed limit

[eNTe]

Hello,
we are using zimbra 7 opensource
we have the issue that some important mails are not received due to max size limit. I cannot believe that there is no hint in the docs. I can't find any helpfull post for this either. The only entry 'wiki/Configuring_maxmessagesize' doesn't work.
Any hints?

zmprov gacf zimbraMailContentMaxSize
: 50000000
zmprov gcf zimbramtamaxmessagesize
: 50000000
postconf message_size_limit
message_size_limit = 25600000

Thank you

[phoenix]

I cannot believe that there is no hint in the docs.

I can't believe you've given no details of the message size being sent, nor the type of message being sent nor any information from the log files to tell us exactly what happened when one of these 'offending' mails was sent.

[eNTe]

Hello,
yes you are right. I became a bit desperate yesterday - after hours of trying to fix the problem.
OK, we need to receive Mails with about 40MB of size. This is an automatic and repeating task, so there is no way to split the attachement.
For that mails I get the entry in zimbra.log:

fetchmail[14334]: SMTP-Fehler: 552 5.3.4 Message size exceeds fixed limit

First I set the MTA Mail max size in the Admin console. But this just seems to relate to the size of mails to send.
Following the wiki article Configuring maxmessagesize - Zimbra :: Wiki doesn't work for me.
So far involved variables:
zimbraFileUploadMaxSize: This is just to upload files to Zimbra? I should not need to change this?

 zmprov gcf zimbraFileUploadMaxSize
zimbraFileUploadMaxSize: 49999872

zimbraMtaMaxMessageSize: This is to define the the max size to send mails? Also to receive? Otherwise I would prefer to keep this small.

zmprov gcf zimbraMtaMaxMessageSize 
zimbraMtaMaxMessageSize: 50000000

zimbraMailContentMaxSize: What is this exactly for?

zmprov gacf zimbraMailContentMaxSize
zimbraMailContentMaxSize: 50000000

postconf message_size_limit: it seems this needs to be adjusted - but how?

postconf message_size_limit
message_size_limit = 25600000

What is the right way to restart what service to have the changed values to take effect. For now I just restarted the whole thing to be sure.
I hope this is all the information you need?
Thank you

[phoenix]

OK, we need to receive Mails with about 40MB of size.

Those sizes you've specified are nowhere near large enough for a 40MB messages to be sent or received, because of the way messages are uploaded to mail servers they can be 30% larger (or more) than the original message size - I'd review your numbers significantly upward.

[eNTe]

Ok, I did change the numbers to 70000000 for all of the three - to no avail.
The smallest mail not getting in is said to be 32MB.
And still I have postconf message_size_limit = 25600000
I will need to change that one, don't you think so? Anyway, I wonder where this number comes from. It usually seems to be set to 10MB. Somehow I must have changed this in the past. But I never played with this before, so maybe I have set this somehow with the zimbra setup.

And I would really like to get some explanation for the numbers. I want to keep everything as small as possible (Its an old, old server).

Any more hints?
Thank you!

[phoenix]

Take a look at this wiki article: Configuring maxmessagesize - Zimbra :: Wiki