552 5.3.4 Error: message file too big

[TobiasG]

Hi,

if a costumer tries to send an email with a bigger attachment, the email is rejected:
Protokoll: SMTP, Serverantwort: '552 5.3.4 Error: message file too big', Port: 25, Secure (SSL): Nein, Serverfehler: 552, Fehlernummer: 0x800CCC6D
I'm using Qmail and the max filesize in the configuration is set way beyond the size of the attachment.
I also changed the settings in Plesk mailconfiguration, so there shouldn't be a problem, too.
I can't find any other way to change some setting concerning this subject.

When I try to send a message with the same attachment, but my own emailadress (same server), I got no problem.
All packages have bin migrated from version 9, but I also tried deleting the affected package and creating a new one, but without any difference in result.

The whole problem seem to occur since upgrading from version 9 to 10.

Any idea?

Best regards,

Tobias

 

[IgorG]

Looks like the problem is that when attachemnt encoded with Base64 encoding every 3 bytes of data are turned into 4 bytes thus increasing size of attachment by 25%. For example, in case of 8 Mb attachment final message size would be 10.6 megabytes (or 11184810 bytes) which will exceed limit set on the server.
You can check current SMTP message limit on Qmail server with:

# cat /var/qmail/control/databytes ; echo

 

[TobiasG]

Thanks so far. Unfortunately this can't be the Problem, because the attachments size is about 30MB and the Qmail limit was set to 209715200 Bytes in "..../databytes" (200 MB ).
It also seems not to occur in every package I created in Plesk (got no probs with my own package/email).

Any other idea?