>From the IMail 8.2x Getting Started Guide (I don't think there are any
>major
changes for 2006):
Processing Order
Incoming mail addressed to a valid local address is processed in
the following order.
1 SMTP Access Control. The SMTPD service checks if the
connecting IP is listed in the Access Control dialog box. If it is
listed in deny access list, the connection is denied. If it is
listed in the grant access list, the connection is allowed and
processing continues.
2 SMTP Kill File. The SMTP service checks if the email
address listed in the "Mail FROM" address command to see if
it is listed in the Kill List. If the address or domain is present,
the SMTP service returns an error to the connecting client and
does not accept the message. If no match is found, the SMTP
service accepts the message.
3 Connection Filtering (DNS Black Lists). If you have DNS Black Lists
enabled, IMail
compares the connecting IP address to the black lists to determine if a
match occurs. If a
match occurs, the email may be deleted (depending on the DNS Black Lists
configuration)
or an X-Header may be added and processing continues.
4 Verification Tests. If you have the verification tests enabled, they
verify the "Mail
FROM" address, the HELO/EHLO domain, and perform a reverse DNS lookup. If
any
of these checks fail, the email may be deleted (depending on the
configuration) or an XHeader
may be added and processing continues.
5 Sender Policy Framework (SPF). If you have the SPF feature enabled, it
provides
increased capability to stop incoming email from forged email addresses.
Using a
sender authentication scheme, a domain owner requires that legitimate
messages from a
domain must meet certain SPF criteria. Messages that do not meet the
criteria are not
accepted as a legitimate email message and are processed according to the
SPF options
selected on the SPF tab.
6 IMail Anti Virus. If you have IMail AntiVirus installed, it checks the
message for
infected files or code. If infected, the mail is repaired, bounced,
redirected, or deleted,
according to the settings on the Anti Virus tab. If the file is not
infected, content filtering
attempts to identify whether the message is spam.
7 Premium AntiSpam. If you have the optional Premium Antispam filter
installed, it
provides automated spam protection in addition to the Standard Antispam
filter
included in IMail. Premium Antispam filter settings are applied before
Standard Antispam
filter settings.
8 Content Filtering. If you have content filtering enabled, it determines
if
the message is
likely to be spam. If the message is determined to be spam, it is either
deleted, sent to
the specified address, or an X-Header is inserted. If the message is not
spam, aliases are
checked.
9 Attachment Blocking. An attachment blocking folder exists for each IP
host
and the
attachment blocking options can be based on the current host or the
primary
host settings.
If you have created and enabled attachment blocking rules, messages that
include
attachment file types that you have identified as file types to block are
blocked from the
message. Attachments are blocked based on message MIME types and filename
types.
You can also define actions to take on blocked messages and a notification
message to
send the message recipient in place of the original file attachment.
10 Alias. IMail Server checks to see if the addressee matches an alias in
the destination
domain. An alias is considered to be one of the following: standard alias,
group alias,
program alias, pager alias, beeper alias, fax alias, or a list-server
mailing list name.
. If there is a match to a program, beeper, pager, or fax alias, IMail
Server executes
the program or activates the beeper, pager, or fax.
. If there is a match to a standard or group alias, IMail Server resolves
the alias to the
appropriate user ID(s), and checks the user ID.
. If there is a match to a list-server mailing list, IMail Server
processes
the mail
according to the settings for that list.
. If there is no match to any alias, IMail Server checks the user ID.
11 User ID. IMail Server determines if the user ID is valid for the
destination domain. If
invalid, the mail is returned to the sender. If valid, delivery rules are
checked.
12 Delivery rules for a list-server mailing list. If the message matches
the
rule criteria for
the list, delivery follows according to that rule. If not, then the
message
is sent to the list
server. If the message is not addressed to a list, Forwarding is checked.
13 Forwarding. IMail Server determines whether an address is present in
the
Forward
box on the General tab for the account. If so, IMail Server forwards the
mail. If not, the
mail is delivered to the user ID according to the established delivery
rules.
14 Delivery rules for the mail host. IMail Server determines if the
message
matches a
rule for the mail host. If so, delivery follows according to that rule. If
not, then rules for
the user ID are checked.
15 Delivery rules for the user ID. IMail Server determines if the message
matches rule
criteria for the user ID. If the message matches rule criteria for a user
ID, then delivery
follows according to that rule. If not, then the Info Manager is checked.
16 Info Manager. IMail Server determines whether the user ID has the Info
Manager
enabled. If so, the automatic response is sent and the message is
delivered
to either the
forwarding address or (if no forwarding address) to the sub-area or
mailbox
specified. If
the Info Manager is not enabled for this user ID, the vacation setting is
checked as
described in the next step.
17 Vacation. IMail Server determines whether the user ID has a vacation
message enabled.
If so, the vacation message is sent. If not, the message is delivered to
the
User ID.
Daniel Donnelly
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Matrosity Hosting
Sent: Monday, September 25, 2006 2:26 PM
To: [email protected]
Subject: Re: [IMail Forum] Order of AV and Spam tests
my understanding from suggesting a different order to ipswitch ts was it
would be a major overhaul to change the order. I wouldn't wait on them
doing
this.
Rod Dorman wrote:
On Monday, September 25, 2006, 12:14:43, David Gregg wrote:
1) IMail anti-virus scanning
2) IMail connection/DNS based anti-spam tests.
Is this really the order it does it in?
What's the point of accepting the entire message if you're gonna reject
based on IP address?
Good point... That's my understanding of the order. Though it would
make
more sense to do the following:
1) IMail connection based anti-spam tests.
2) IMail anti-virus scanning
3) IMail DNS based anti-spam tests.
Then the rest as detailed before.
IMHO getting to the DATA phase and doing CPU intensive tests (like
anti-spam scanning) should be after any DNS tests.
Perhaps the Ipswitch guys can chime in on this one
Indeed, an authoritative answer would be nice.
