1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
Qmail Multiple Queue (Option) -- QMQ(0)
---------------------------------------
1. What is QMQ ?
Qmail Multiple Queue -- is an option (of SPAMCONTROL).
SPAMCONTROL is useful on Qmail hosts attached to the
Internet and receiving e-mails, shortly named MTA
(Mail Transfer Agents).
While SPAMCONTROL tries to take control of the
incoming SMTP traffic, QMQ allows you to control
the e-mail communication to -- and from -- the
(downstream) e-mail domains you are responsible for.
2. How does QMQ work ?
In addition to standard Qmail (patched with SPAMCONTROL)
to receive e-mails from the Internet, you set up > N <
secondary instances of Qmail to deliver e-mails to your
downstream domains.
The different Qmail instances are typically set up on
one host; the communication from the primary instance to
the secondary is faciliated by QMTP, though SMTP can be
used as well.
While the primary instance is patched with SPAMCONTROL,
all seconderis can be plain (Vanilla) Qmail.
Once the primary Qmail instance receives an e-mail for
a QMQ domain, it will forward the e-mail via QMTP to
one of the secondary instances, which is responsible
for furthter delivery.
This not only will avoid the so-called "Silly Qmail
Syndrom" but will allow you to fine-tune the delivery
conditions and set-up (e.g. Virus/Spam scanners)
for any recipient domain.
3. How to set up multiple Qmail instances ?
You are free to set them up.
However, you can use the scheme, I have developed:
a) Modify "conf-qmq" to your needs.
Here, you define the (local) instances by name
and their (QMTP) port numbers.
b) Execute ./qmtpt ..../ . This will raise
- ./qmail/skeleton --
- ./qmail/source
4. What is the benefit of QMQ ?
a) Decoupling: Delivery to domain >i< is independent
of domain >k<.
b) Independent delivery parms and perhaps filters for
any secondary domain.
c) Primary instance does not suffer from "Silly Qmail
Syndrom".
d) Set up of a dedicated Bounce Queue.
e) Thruput is increase by a factor of 10 - 100.
5. Consideratons:
a) Using 'qmail-qstat' practically, very littly
e-mails stay in step 'preprocessed' (on the
primary instance) will be realised.
b) Adjust your delivery channels to your needs.
With QMQ, Qmail will easly flood them up.
Erwin Hoffmann
Cologne, 17-08-2007
|
