quota_over_flag examples?

[Gedalya]

On 04/16/2015 05:35 AM, E.B. wrote:
> I can't find any posts on this list for peoples using quota_over_flag
>
> http://wiki2.dovecot.org/Quota/Configuration#Overquota-flag_.28v2.2.16.2B-.29
>
> If my userdb is sql what would be best script to use in terms of performance?
> (I mean if over-quota-flag triggers script every time it changes and the script
> calls CLI mysql client isn't all this so expensive to spawn a new shell session
> which spawns a mysql client?)
I have a post-login script updating a "lastlogin" timestamp every time a 
user logs in. This can happen many times per second in busy hours. The 
only noticeable load is on the mysql _server_ (namely, some I/O). The 
shell + mysql client load is not noticeable at all. Don't use bash, of 
course!
Now if we're talking about updating a flag when a user comes back under 
quota? How frequently is this expected to happen?

>
> Anyone knows how to use this flag with postfix *making postfix send
> special reject* "user over quota" note instead of plain SMTP reject??
> Is an additional database lookup (restriction class?) unavoidable? :(
I don't actually use this, but try perhaps:
https://sys4.de/en/blog/2013/04/08/postfix-dovecot-mailbox-quota/

And perhaps search the mailing list for "quota-status" for more info.

> TIA1
>
> PS Looks like it is tricky almost impossible to make postfix do rejects
> based on this flag for aliases.  (Special query would be a little messy
> for our schema but i dunno at what point postfix resolves aliases?)

Tough one. It gets more complicated: What about aliases expanding to 
multiple recipients? I figure the options are:
* Reject (or defer) the RCPT TO because of the one offender who's over quota
* Accept, and deliver only to within-quota recipients, silently drop out 
the over-quota ones
* Let a bounce message go out in this case, as necessary

I don't know how it's done with postfix, anyway...