Re: avoiding overload on port 587
- On 11/30/2012 6:08 PM, Wietse Venema wrote:
> Stan Hoeppner:My apologies for the mis-attribution Wietse. I agree not all virtual
>> That said, given the ongoing clock issues that all the guest/hypervisor
>> combos have always experienced to some degree, and will forever
>> experience no matter how good the mitigation hacks, it is my opinion,
>> and Wietse's, and many others, that mail is not really a suitable
>> application for most virtual environments. I'm sure you'll now write at
> Um, I have pointed out failures. I do not claim that all virtualization
> environments fail to meet the requirements.
environments have clock problems serious enough to avoid deploying mail
servers. I stated "most", which may likely be better described today as
"many". It's still a problem with Linux on ESX though not as bad as it
once was, and it's bad today with Linux on Linux. I would think with
IBM's ingenuity and 30 some years of virtual machine experience that
Linux on zSeries would have no clock drift at all, but I have no first
hand experience with this platform, and I have no experience and pay no
attention to what Oracle is doing with Solaris virtualization,
"containers" I believe they call it.
- On Tue, Dec 04, 2012 at 07:46:10AM -0600, /dev/rob0 wrote:
> On Tue, Dec 04, 2012 at 11:59:01PM +1300, Peter wrote:Or better yet: replace it with postscreen.
> > I would still also set up port 587 on the mail.example.com
> > IP as submission as well and try to encourage your users (at
> > least the ones you can) to use port 587 from now on.
> What I would do, on Linux with IPv4 only, is create the submission
> port and use an iptables redirect for the alternate IP address:
> # iptables -vt nat -A PREROUTING -p tcp --dport smtp -d \
> mail.example.com -j REDIRECT --to-port submission
> This saves the overhead (system and administrative) of running
> another smtpd on [mail.example.com]:25; he can leave his "smtp ...
> smtpd" service alone in master.cf.
> I should also add as a reply to Stan in the other subthread: lookTo clarify, I meant that if those Outlook Expresses are not yet
> above at the first quoted paragraph: "Outlook Expresses setup with
> ... default configuration."
> Yikes, bad news, very bad. If not doing content filtering nor
> policy limitation of submission now, he will be soon. And possibly
> losing his job in any case. Tomas is not in a good place right now.
compromised by malware, they will be, soon.
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