Re: ****Re: [OT] HELP!!! mail attack

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Craig White wrote:



You are correct of course, that nowhere does it state that sender MUST attempt to re-deliver. I do wonder if you would find an SMTP server that by default didn't attempt re-delivery on temporary failures to be acceptable. It MUST be configurable - that's it.


Okay, so Tim wasn't sure, but now we agree retrying, while it might be good practice isn't essential.


I've just done a "host -t mx" for several companies. Most have four mail exchangers, one had a dozen. While those are for incoming email, it's likely that they generally have a similar number for outgoing email. Without information, I assume that to be so. In many cases they will be the same machine.

I don't know what their retrying policies are, but I can imagine that retrying might involve an attempt by each of several machines, each getting a 4XY response.

It might be a lengthy delay, it might result in email getting returned to sender.

Tim is right in his belief that greylisting can cause delivery problems. You don't have to think it's as big a problem as he does, but I don't criticise him for seeing it as a risk he doesn't want to take.


Here is one list of recommended delays between retries:
http://www.mailenable.com/Help/Files/smtpdelivery.htm


The use of fake mx records suggested here looks enticing:
http://wiki.apache.org/spamassassin/OtherTricks

I discontinued using a second mx because it seemed only to receive spam, and senders _should_ retry if I'm not listening.



--

Cheers
John

-- spambait
1aaaaaaa@xxxxxxxxxxxxxxxx  Z1aaaaaaa@xxxxxxxxxxxxxxxx
-- Advice
http://webfoot.com/advice/email.top.php
http://www.catb.org/~esr/faqs/smart-questions.html
http://support.microsoft.com/kb/555375

You cannot reply off-list:-)

--
fedora-list mailing list
fedora-list@xxxxxxxxxx
To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
[Index of Archives]     [Older Fedora Users]     [Fedora Announce]     [Fedora Package Announce]     [EPEL Announce]     [Fedora Magazine]     [Fedora News]     [Fedora Summer Coding]     [Fedora Laptop]     [Fedora Cloud]     [Fedora Advisory Board]     [Fedora Education]     [Fedora Security]     [Fedora Scitech]     [Fedora Robotics]     [Fedora Maintainers]     [Fedora Infrastructure]     [Fedora Websites]     [Anaconda Devel]     [Fedora Devel Java]     [Fedora Legacy]     [Fedora Desktop]     [Fedora Fonts]     [ATA RAID]     [Fedora Marketing]     [Fedora Management Tools]     [Fedora Mentors]     [SSH]     [Fedora Package Review]     [Fedora R Devel]     [Fedora PHP Devel]     [Kickstart]     [Fedora Music]     [Fedora Packaging]     [Centos]     [Fedora SELinux]     [Fedora Legal]     [Fedora Kernel]     [Fedora OCaml]     [Coolkey]     [Virtualization Tools]     [ET Management Tools]     [Yum Users]     [Tux]     [Yosemite News]     [Gnome Users]     [KDE Users]     [Fedora Art]     [Fedora Docs]     [Asterisk PBX]     [Fedora Sparc]     [Fedora Universal Network Connector]     [Libvirt Users]     [Fedora ARM]

  Powered by Linux