Re: Snow Leopard Server Mail Settings?

On Mar 5, 2013, at 6:23 PM, Ashley Aitken <[email protected]> wrote:

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> Hi,
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> I'm having some problems with Snow Leopard Server email (mail bouncing or t=
aking a long time to get in, an hour or more, in some cases).
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> Can someone please help with clear definitions for (and the purpose of) th=
ese settings in the Mail Service > Settings > General tab in Server Admin?
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> 1. Domain name: =20
> Enter the local Internet domain name.
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> What exactly is this meant to be (and how is it used)?
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> Currently this is set to "local"
> I only have one server that runs mail and web behind our ADSL modem/router=

> Hopefully, ports are forwarded as appropriate from the modem/router to the=
 server
> I do have an internal DNS setup, with the same domain as external for when=
 clients are connected locally.
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> 2. Host name:
> Enter the Internet host name of this mail system
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> What exactly is this meant to be (and how is it used)?
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> Currently this is set to "mydomain.com"
> I would have thought that the Internet host name would have been mail.mydo=
main.com as in the MX record?
> I think I have used that in the past but my email addresses then looked li=
ke name-i4yH9JU3wRtWVPTZF4YnfwC/[email protected] :-(
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> 3. Mail > Settings > Relay=20
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> With regards to the delay of emails getting accepted (when they don't boun=
ce and only from some servers it seems, e.g. Apple mac.com delivered immedia=
tely)
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> I thought this was caused by my using some  "junk mail rejection servers (=
realtime blacklist)"
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> However, I've check again and I no longer seem to have any of these config=
ured (are they recommended? which ones?) so something else must be slowing d=
own the mail delivery. =20
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> I notice in the mail.log lots of entries like this:
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>> Mar  6 12:09:06 server postfix/smtpd[52216]: connect from mailserver.east=
erncontrols.com[70.90.14.220]
>> Mar  6 12:09:07 server postfix/smtpd[52216]: NOQUEUE: reject: RCPT from m=
ailserver.easterncontrols.com[70.90.14.220]: 450 4.7.1 <info-3Q2Tfjf0mew0n/[email protected]=
>: Recipient address rejected: Service is unavailable; from=3D<upchucksenn4@=
gmail.com> to=3D<info-vF6D3zRCt/[email protected]> proto=3DESMTP helo=3D<mailserver.e=
asterncontrols.com>
>> Mar  6 12:09:08 server postfix/smtpd[52216]: lost connection after DATA (=
0 bytes) from mailserver.easterncontrols.com[70.90.14.220]
>> Mar  6 12:09:08 server postfix/smtpd[52216]: disconnect from mailserver.e=
asterncontrols.com[70.90.14.220]
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> I thought this was the realtime blacklisting.
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> I also see lots of these:
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>> Mar  6 12:10:42 server postfix/anvil[51922]: statistics: max connection r=
ate 5/60s for (smtp:68.203.211.226) at Mar  6 12:06:03
>> Mar  6 12:10:42 server postfix/anvil[51922]: statistics: max connection c=
ount 2 for (smtp:134.7.73.150) at Mar  6 12:04:27
>> Mar  6 12:10:42 server postfix/anvil[51922]: statistics: max cache size 4=
 at Mar  6 12:05:25
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> Are these just spam sites or is something wrong my end?
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> I have checked my email service from outside, using the Web sites that che=
ck, and it all seems fine - no open relay, mail server matches reverse dns, e=
tc. =20
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> Thanks in advance for any assistance.
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By default, greylisting is turned on. That's the issue you're having. This d=
elays email being delivered to reduce spam. Spammers will rarely if ever ret=
ry a send., If it fails, they give up after one. But a properly configured s=
erver will try again after a given interval.

This explains how to turn if off. Be careful though because it can accidenta=
lly get turned on. Apple's server admin doesn't respect hand edited configur=
ation files very well.

http://labs.hoffmanlabs.com/node/1755

To answer your questions in order.

1. Your internet domain should be one of the domains that you receive mail f=
or such as : blahblah.com.

2. The host name is the public host name of the system (your MX record will t=
ell you what this should be). mail.blahblah.com would be a common one for th=
e domain in #1.

3. This where the greylisting comes into play. Turn it off and you'll be fin=
e.

You should also set up a reverse DNS lookup for your mail server's public na=
me. Some servers will reject mail that doesn't have a correct reverse DNS lo=
okup. Your ISP can do this for you since they control the DNS for the IP add=
resses that they give out to their customers.=