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POP3 Flooding

Discussion in 'General Discussion' started by sparek-3, Dec 29, 2004.

  1. sparek-3

    sparek-3 Well-Known Member

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    I'm using the POP3 flood protection. I have it set to allow 60 connections per hour. My question is, is this 60 connection per POP account or 60 connections per IP? What does it base a connection on?
     
  2. bigj

    bigj Well-Known Member

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    From my experience it's based on max connections per IP. I had enabled it a few months back and a very large coporate office began reporting they couldn't connect to check mail. They are behind a firewall thus they are all coming from a single IP and were exceeding the max connections.

    I disabled it and viola, back online.

    bigj
     
  3. ntwaddel

    ntwaddel Well-Known Member

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    yeah, i had to disable it also.
     
  4. sneader

    sneader Well-Known Member

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    I disagree... it is checking the max connections per ACCOUNT, not per IP. Maybe it was changed from the time this thread was started, but as it is now, it is misinformation.

    Personally, I am behind a NAT router and between all the computers here, about 15-20 POP3 mailboxes are checked every 10 minutes. Yet, I have the max POP connections set to 30 per hour (allowing users to check mail every 2 minutes or less) and it works fine.

    Also, a customer can exceed the max connections if they check mail from mulitiple locations at the same time. It is because it is counting the number of POP3 logins per hour, and does not look at or care about the IP address.

    That is my experience anyway.

    - Scott
     
  5. sawbuck

    sawbuck Well-Known Member

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    Unfortunately that limitation is not being enforced for those of us that have moved to maildir from mbox.

    http://bugzilla.cpanel.net/show_bug.cgi?id=3665
     
  6. bigj

    bigj Well-Known Member

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    I wasn't clear when I posted this over a year ago. My problem was this:

    1) I had 'The number of times users are allowed to check their mail using pop3 per hour' set to unlimited.
    2) I also had 'Attempt to prevent pop3 connection floods' enabled.

    So my problem was being caused by #2 which will prevent a pop3 flood from occuring if some unknown number of connetions have opened from the same IP within some unknown amount of time. Wish I knew what the unknown numbers were though.

    I knew this was the fix because as soon as I disabled it (#2) the problem went away. No other customers (350 customers/domains at that time) ever complained about not being able to get e-mail other than this one customer.

    Additionally this customer had 65 mailboxes and most everyone was checking mail every minute (silly rabbits).

    --
    bigj


     
  7. Drew Nichols

    Drew Nichols Well-Known Member

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    We are running into this with a handful of customers. What do you do to handle that many connections on a shared account? I know - don't oversell. The thing is if you have it set at 100, an office with 8 users will generate 480 POP's an hour, overwhelming this. Eight workers, I tell you. :) You'd think that offering 10 mailboxes with a $20 account would be reasonable, but I guess not?
     
  8. sneader

    sneader Well-Known Member

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    You are wrong in how you think it is working. It does NOT work that way. It doesn't matter how many accounts are being checked at that office. It counts the number of checks per ACCOUNT, not per IP ADDRESS.

    I have mine set to 30 per hour. If anyone needs to check their e-mail MORE than every other minute, they can go elsewhere and I'll gladly refund their money. It is not reasonable.

    - Scott
     
  9. bigj

    bigj Well-Known Member

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    Jeez, didn't know this was such a touchy topic. I'm removing myself from e-mail notification on this thread from here on out.

    --
    bigj
     
  10. Drew Nichols

    Drew Nichols Well-Known Member

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    It's per *domain* account, not actual POP3. So a domain with two users can only check every 4 minutes under your situation. Fair enough - I turned off auto check by design on my personal Outlook. When I'm free to read mail, I just hit "send/recv". :cool:
     
  11. sneader

    sneader Well-Known Member

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    I think we are talking about THREE different options here, all under Tweak Settings.

    1. Attempt to prevent pop3 connection floods -- the WHM documentation describes this as "Limit the amount of connections from each host to the POP3 server."

    2. The number of times users are allowed to check their mail using pop3 per hour -- the WHM docs say "Enter the number of times users can check their POP3 mailboxes per hour."

    3. The maximum each domain can send out per hour -- WHM docs say "Enter how many e-mails one domain can send per hour."

    As you can see, each limitation is looking at the source differently.... host (IP address?), user (each POP3 account user) and domain (self explanatory).

    My comments are only about #2 and I am using that feature very successfully to keep individual POP3 users from hammering the server. Sorry for any confusion I may have caused. I do not know anything about #1 or #3.

    - Scott
     
  12. sawbuck

    sawbuck Well-Known Member

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    Best not to update to Courier/maildir then as the limits don't apply and apparently are not going to as according to cPanel support, "Courier doesn't support this option".
     
  13. dexus

    dexus Well-Known Member

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    Does anyone know what exactly is that number of connection after which 'prevent pop3 connection floods' will block pop connections, and for how long?

    Does anyone know anything more specific about this option?

    Thanks.
     
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