Initial situation:

The SEPPmail Secure E-Mail Gateway is integrated into the email flow. An outgoing system is trying to send an email to the SEPPmail Secure E-Mail Gateway. In the process, the email is temporarily rejected by the SEPPmail Secure E-Mail Gateway with the message "452.3.1 Insufficient System Storage", although the email partition (see Home Disk statistics Mail queue) is still displayed with approx. 40% free storage.

 

Cause:

This is a security function of the Postfix integrated for email processing. This ensures that sufficient memory is available even if a new email has to be multiplied, for example, due to multiple recipients.