limit pop login per user and per minute

[Robert Schetterer]

Am 22.03.2018 um 12:42 schrieb Robert Schetterer:
> Am 22.03.2018 um 11:21 schrieb Markus Eckerl:
>> Hi,
>>
>> like I have written in the subject line I want to limit the pop login
>> per user and per minute.
>>
>> Currently I am having several customers which are fetching their email
>> with popcon (MS Exchange).
>>
>> This has never been a problem. But... They all have got the same
>> "technician" which take care of their systems.
>>
>> The problem is, that he misconfigured the servers of these customers. In
>> detail: their servers are trying to fetch email every 2 - 5 seconds. For
>> every email address.
>>
>> In the past I contacted the technician and told him about his mistake.
>> He was not very helpful and simply told me that he is doing the same
>> configuration since several years at all of his customer servers.
>> Without problems. It is up to me to fix my problem myself.
>>
>> Well, I googled a lot but all I found is to limit for a specific IP or
>> for a secific account. Both is not what I am looking for.
>>
>> Maybe someone can give me a hint?
>>
>> Thanks and kind regards
>>
>> Markus
>>
>>
>>
> 
> I had about 5000 popcon users in the past , dovecot can handle this
> if you turn right parameters on. As far i remember there were also 2
> different ways to configure popcon, users per time or all users in one
> session ( which was really bullshit ) , after all i wouldnt recommand
> trying limiting ,that might lead to further problems. Your customer has
> to understand his misconfiguration
> 
> some graph of that time is here
> 
> https://blog.sys4.de/xymon-dovecot-count-imap-pop3-logins-graph-central-rsyslog-server-ubuntu-lucid-en.html
> 
> 
> 
> 

beside iptables recent, or fail2ban
which may have unwanted side effects and only work by ip

here was a post with a dovecot solution

https://www.dovecot.org/list/dovecot/2017-July/108521.html

never tested this


Best Regards
MfG Robert Schetterer

-- 
[*] sys4 AG

http://sys4.de, +49 (89) 30 90 46 64
Schleißheimer Straße 26/MG, 80333 München

Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263
Vorstand: Patrick Ben Koetter, Marc Schiffbauer
Aufsichtsratsvorsitzender: Florian Kirstein