"0" as mailbox quota counts as zero but works as infinite
short description
Client with 2 GB of Mailspace creates mail-account and sets quota to 0. Instead of rejecting all mails, the server takes all mails an client never gets a quota warning.
correct behaviour
Either 0 is infinite quota, then it should be impossible for the client to set it to 0. Or 0 is zero, then no mails should be accepted.
environment
Server OS: debian Server OS version: jessie ISPConfig version: 3.1.13
references
#5586 seems to mention the same issue