[SOLVED] Maximum allowed attachment size

[Bill Brock]

What is the limit and can I increase it.

[mmorse]

Two fields: zimbraMtaMaxMessageSize & zimbraFileUploadMaxSize

You might to set zimbraFileUploadMaxSize 10-30% > than your attachment.
Also as a general rule, I set zimbraMtaMaxMessageSize 10% larger than the zimbraFileUploadMaxSize.

Say both are set to 10MB (and you tell everyone they can send 10MB attachments):
An email with a 9MB attachment and 100KB message body text. The attachment may be less than the 10MB zimbraFileUploadMaxSize, and so it'll get accepted by the file upload system. But when it's converted into a MIME message it ends up base64-encoded. Then add 100K of regular body text, and the resulting message (say 10.3MB or so) is then handed off to postfix, which checks zimbraMtaMaxMessageSize and promptly rejects the message if it's over the limit of 10MB. (behavior will change in Bug 27610 - Use zimbraMtaMaxMessageSize exclusively for mail, and use zimbraFileUploadMaxSize for docs/briefcase)

Of course that would mean that you would set zimbraMtaMaxMessageSize even larger if you want to allow emails with multiple large attachments.

5.0.x is missing a field in the admin console > global settings: Bug 23996 - restore the UI field, corresponding to the zimbraFileUploadMaxSize attribute, in Admin console

You can both of them via the command line like so:
zmprov gacf | grep zimbraFileUploadMaxSize
zmprov mcf zimbraFileUploadMaxSize #
&
zmprov gacf | grep zimbraMtaMaxMessageSize
zmprov mcf zimbraMtaMaxMessageSize #

[mmorse]

When you're increasing it keep in mind that the servers at the other end have to be able to accept the larger size
10MB has kinda been the 'standard' if you plan to go larger than 100MB on a regular basis be sure to do some email tests to see if your recipients can handle it.
In 5.0.x you can also make use of the briefcase to share larger files.

[Bill Brock]

I tried to send a 6.9MB attachment and it told me it was too large. Is this larger than the default?

Thank you for your prompt answer. I'll check the two settings you mentioned.

[Bill Brock]

After checking the settings which are set to 10MB I am confused as to why Zimbra refused a 6.9MB attachment. It uploaded it but said it was too big to send.

[Costa-101]

Did you restart after changing the setting ?

[Bill Brock]

Those were the defaults. I didn't have to change any settings.

[mmorse]

Run it through UUDeview (windows app) which will help you find out just how much larger a MIME (or UU-encoded) version of a given file will be - try 'base 64' in the encode settings. (Won't wreck your current file, it creates a converted duplicate.)

[Bill Brock]

original: 6,463,488

base64: 8,844,875

[mmorse]

hm, does it go through if you increase both values to like 15MB?