Selcuk Yazar wrote:

>when i looked up in to postfix log
>  module=Quotas, action=reject, host=91.211.240.240, 
>helo=<http://pmta240240.emarsys.net>pmta240240.emarsys.net, 
>from=<mailto:[email protected]>[email protected],
> 
>to=.....@<http://trakya.edu.tr>trakya.edu.tr, reason=quota_match, 
>policy=2, quota=3, limit=4, track=Policy, counter=MessageCount, 
>quota=71.27/70 (101.8%)
>
>what is it mean , i want to restrict mails for totaly 70 per hour
>how can i do that ? are thre detailed documentation or tutorial for 
>achieve this. ???

The rate limit isn't a hard "in any period of x seconds, no more than 
y messages will be passed", it's done slightly differently.

Each time the calculation is done, the counter is reduced in 
proportion to the length of the rate limiting period and time since 
last message, and then incremented if the message is passed. SO if 
you had a limit of 10 messages per 10 units of time, then it might 
run like this.

You send lots of messages and get the rate up to 10. After one time 
unit you attempt to send another message. The calculation goes like :
new_rate=old_rate * ( 9/10), so it gets set to 9. 9 is less than 10 
so the message is passed, and then the rate is incremented to 10.

Now you send another message after just half a time unit. This time 
the new rate is 10 * ( 9.5/10) = 9.5. The message is passed, but the 
rate now goes up to 10.5.

If you try and send another message now then it will be blocked, and 
won't be passed until about another half a time unit has passed when 
the rate will again have reduced to 10 or below.

So if you just keep trying to send messages, you will find that they 
are in fact rate limited to the rate you set, but the edge may appear 
to be a bit fuzzy. Also, there is inherently a burst capability.

Assume you've not sent any messages for 10 time units. The rate is 
now down to zero, and you can squirt 10 messages through in quick 
succession. In practical terms you won't get them through at 
*exactly* the same time, so the rate will be 9.9<something>. So it 
will appear that you can get 11 through which breaks the rate limit. 
However, to do this you must have sent no messages for a while (AND 
you won't be able to send another for about 1 time unit), and so your 
time averaged rate will be limited to about the rate you set.


PS - can you please find the plain text option in your mailer ?
-- 
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.
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