On 29/07/2015 11:56, Chris Knadle wrote:
> On 07/27/2015 07:03, Paul Stuffins wrote:
>>> Instant question: what is your load? Why separate servers?
>>> You're adding a lot of complexity by insisting on that.
>>
>> My load at the moment is not that huge, I think I get a couple hundred
>> emails a day, most of them are spam even with my current spam solution
>> in place.
>
> A single box running Exim, the spam filtering, and the mail storage can
> handle a LOT more mail than a few hundred mails a day.
>
> Referring to your original post:
> https://lists.exim.org/lurker/message/20150726.191522.50e7b2a9.en.html
>
> For spam filtering have a look at the exim4-daemon-heavy package in
> Debian which contains the exiscan-acl patch. What's really nice about
> this is that this can call the spam filtering late in the process, so
> you can do a lot of CPU cheap checks up front, and allows for
> denying/rejecting the mail after spam classification rather than having
> to do "accept then drop". With many cheap checks so that the spam
> filtering is only done when needed, a box running Exim can deal with
> thousands of messages a day at < 1% CPU load.
>
>> As for wanting separate servers, mainly for upgradeability. If I
>> want/need another SMTP relay, I don't really want to install all the
>> spam/av stuff on it and same for the datastore.
>
> Re: upgrade-ability: if your concern is downtime then you could
> "simulate" the Debian upgrade via duplicating the packages and
> configuration in a VM, make a snapshot of the VM, and then test what
> happens when you upgrade. This allows you to know what's /going/ to
> happen, so you can do all of the configuration changes that are needed
> and have those files ready for the /real/ upgrade.
>
> If you split the mail service up into several servers, tracing a single
> mail via logs becomes a lot more work, and instead of dealing with
> upgrades for only one box now you've got several, and a more complicated
> DNS structure to route the mail too. I've created these kinds of setups
> professionally, but I think it's better to avoid that if you can. The
> breakpoint I think is > 500 mailbox users and/or dealing with more mail
> than a single box will handle.
>
> The HowToForge link you found looks interesting, but a bit overkill...
> it does mail routing via LDAP, which I used to do, and it complicates
> adding users because it requires making a new LDAP entry. This is
> really meant for when there are multiple mail stores so that each user's
> mail can be routed differently. If you're only doing your own mail
> right now, you won't need this; it's possible to do Virtual Users via
> text file lookups too, and it's a lot more convenient to add entries via
> a text editor.
>
> Realistically I think the best place for you to start is a simple setup
> with Exim in a VM. Take some time to get a feel for how to configure it
> and what kinds of setup work for you.
>
> -- Chris
>
Hi Chris,
Thanks for your input, as this is my first journey into Exim, and first
mail server that I will not be simply copy/pasting from a tutorial, then
I think I will, as you say, start simple and work from there.
Thanks
Paul
