Resolved Is email limit per hour each clock hour or a sliding window?

[David Marcus]

How does the email limit of 300 per hour work? Is it

1. Per each clock hour (e.g., 3:00 to 4:00, 4:00 to 5:00),

2. The number of emails in a sliding window of the previous hour from
now (e.g., if it is now 3:25, then 2:25 to 3:25),

3. When you hit the limit, you can't send for the next 60 minutes?

I reached the limit and Plesk displayed

Attempts to send mail after exceeding the limits during the reporting period:
Started At Back To Normal At Rejected Messages
Oct 25, 2016 07:27 PM Oct 25, 2016 08:23 PM 4

This makes me think it is a sliding window.

Plesk version: psa v12.5.30_build1205150826.19 os_RedHat el6

 

[SKDamon]

For completeness' sake (this is the first result on google for "plesk mail limit sliding window"):

From my tests, it looks like a sliding window is used. So:
1. Limits are checked (nearly) real-time
2. That's right
3. That's right

I set up a mail address w/ limit of 2 outgoing mails per hour. Sent 1 Mail at 10:00 and the other one at 10:05. I was able to send the third mail at 11:01 and the fourth was only accepted by my plesk mailserver at 11:06.

 

[Bitpalast]

Sliding window.