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delay receiving email

Discussion in 'E-mail Discussion' started by jlucho, Jul 24, 2018.

  1. jlucho

    jlucho Active Member

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    I have a question, hopefully you can guide me if it is a problem in the server, in the network, or it is external.


    Some emails are received with excessive delay.

    In my case, in my server for personal use, there are paypal emails that delay in arriving.

    For example, there is a paypal purchase at 5AM and at 11:50 AM the confirmation email does not arrive yet.

    although the delay, also happens with other suppliers or senders
    there are other email providers, which do arrive quickly
    hotmail, gmail , arrive quickly


    The resolv.conf I use are:

    cat /etc/resolv.conf
    # Generated by NetworkManager
    nameserver 208.67.222.222
    nameserver 208.67.220.220

    The incident of the delay in receiving mail, will be some problem in the servers? net ? or will it be external?
     
  2. rpvw

    rpvw Well-Known Member

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    I have noticed the same thing, and I tracked it down to my use of greylisting.

    Mail from services like PayPal and my Bank and my ISP uses a number of different IPs to send on, and this causes greylisting to effectively reset each time a new IP in their pool is used - it can take considerable time until the PayPal etc server uses the same mail IP again, and it passes greylisting and gets delivered.

    I don't know what the answer is here - switch off greylisting and get emails instantly ..... plus an avalanche of spam - or leave greylisting switched on and wait (im)patiently :-D

    Of course, one could whitelist the IPs for your service, but if the service uses a lot of them, it is a labour of love if you cant get a published MX list for them. You can see some of the problems just by looking at https://www.paypal.com/us/smarthelp/article/what-are-the-ip-addresses-for-live-paypal-servers-ts1056

    Of course, if you don't use greylisting, you could be having a different issue altogether !
     
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  3. cPanelMichael

    cPanelMichael Forums Analyst
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  4. keat63

    keat63 Well-Known Member

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    I disabled Greylisting for this exact reason.
    Some of our larger customers have many ip's on thier mailserver.
    Greylisting would see each retry as a different server, putting the mail back in to a holding queue.
    Some emails could be held for days if greylisting was too strict.

    Whilst in principle GreyListing is a good idea, in practice, it doesn't work.
     
  5. rpvw

    rpvw Well-Known Member

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    I agree with @keat63 in principle, but I wonder if there is something that could be done to enhance the accuracy and functionality of the greylisting ?

    My knee-jerk reaction was to allow trusted hosts by (user defined) domain names as well as by IP - I realise that then opens up the spam to spoofed mail domains for the domains that have been trusted, but it might prove to be significantly better than no greylisting at all.

    Additionally, the old bypass for valid SPF has become somewhat redundant as too many spammers are setting that record - but I wonder if one could add a bypass for a DKIM and/or possibly DMARC pass, and whether it would be of any use ?

    Any thoughts would be appreciated.
     
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  6. cPanelMichael

    cPanelMichael Forums Analyst
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    Hello @rpvw,

    We have an existing feature request open to request some enhancements to the Greylisting feature:

    Greylisting -- requesting enhancements

    However, it's worth opening a separate feature request if you'd like to see an option to automatically whitelist hosts that pass DKIM and/or DMARC verification.

    Thank you.
     
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  7. rpvw

    rpvw Well-Known Member

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    Thanks @cPanelMichael but cPanel has the only fully working software simulation for general relativity, that proves the existence of black holes.

    Once a feature request passes the event horizon (after sitting orbiting for days waiting for a moderator approval) it then disappears, never to be seen again, sucked down into some dark singularity that is the database of feature requests, and it might (if one is very lucky, or the moderator is having a good day) end up as far up as on page 34 in any of the lists that are presented to browse through. You should offer it to NASA or CERN - they could use it as a teaching aid !

    I really just wanted to provoke a discussion - someone else can have the disappointment of starting the feature request :-D
     
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