Email account disk usage incorrect

Posted on December 29th, 2006 by Alex P..
Categories: Cpanel Hosting, web Hosting, EXIM, VPS / OpenVZ.

Greetings ,

You can use the following command to remove the belows files from all users account on server.

find /home/*/.cpanel-datastore/ -name “diskusage_*” | xargs rm -f
find /home/*/mail/ -name maildirsize | xargs rm -f

Alex

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What is Spam Assassin and How it is work ?

Posted on December 26th, 2006 by Alex P..
Categories: Cpanel Hosting, Linux, web Hosting, EXIM, VPS / OpenVZ.

What is Spam Assassin ?
The SpamAssassin system is software for analyzing email messages, determining how likely they are to be spam, and reporting its conclusions. It is a rule-based system that compares different parts of email messages with a large set of rules. Each rule adds or removes points from a message’s spam score. A message with a high enough score is reported to be spam.
Spam Assassin is a e-mail spam filtering system that sits side by side with account with us to help block, mark or filter out mail you don’t want.

How do I access Spam Assassin?
First thing you will want to do is log into your cPanel. From there, under the “Mail” box look at the nine a link that reads “Spam Assassin”. From here it will tell you if Spam Assassin is currently enabled or disabled. Clicking the boxes to enable or disable Spam Assassin is how you can turn it on or off. To configure the Spam Assassin settings click the button that reads: “Configure Spam Assassin (required to rewrite subjects)”

How do I configure Spam Assassin?
If you do not know what it is you are looking at, the next screen could be a little confusing. To help you understand here’s a break down of what you should see on the screen and what do do with it:

required_hits - The number of e-mails received before marked as spam.
rewrite_subject - The tells Spam Assassin if it should rewrite your subject line or not as you define. (1 is yes and 0 is no)
subject_tag - What the spam is marked with in the subject line. (usually ***SPAM*** or something else that could be picked up by your own mail filters on your mail client of choice)
blacklist_from - An e-mail address you definitely want to be marked as spam. (you could also use *@something.com to get every email from that address filtered)
whitelist_from - An e-mail address you definitely do NOT want to be marked as spam. (you could also use *@something.com to get every email from that address NOT filtered)

Once you’re done, just hit save and whatever you defined on the earlier page will now be in effect. If you picked to rewrite the subject, then you could now go into your mail client and write a new “rule” that would filter all mail with “***SPAM***” to go into a SPAM folder so that you could check it from time to time making sure you did not get any false positives.

How do I use the Spam Box ?
You can turn your spam box enable and disable from the same page as Spam Assassin. It’s just that easy! With the recent upgrades to cPanel, the TotalChoice Hosting team has been paying more attention to the users of Spam Assassin.

In the previous build you would need to use a imap client to get to your spam box.
Well not anymore. You can create a “new” e-mail account that has precisely the same settings as your e-mail account, but add: “/spam” to the end of the e-mail account user name. This will retrieve only your Spam Box mail.

In order for this to be useful, you will want to set up your e-mail client to deliver this Spam Box mail to a special folder (perhaps called spam?) automatically.

How spamassassin works

Check out its feature on how it works.

–> There are several ways that SpamAssassin makes up its mind about a
message:
–> The message headers can be checked for consistency and adherence to
Internet standards (e.g., is the date formatted properly?).
–> The headers and body can be checked for phrases or message elements
commonly found in spam (e.g., “MAKE MONEY FAST” or instructions on how to be
removed from future mailings)-in several languages.
–> The headers and body can be looked up in several online databases that
track message checksums of verified spam messages.
–> The sending system’s IP address can be looked up in several online lists
of sites that have been used by spammers or are otherwise suspicious.
–> Specific addresses, hosts, or domains can be blacklisted or whitelisted.
A whitelist can be automatically constructed based on the sender’s past
history of messages.
–> SpamAssassin can be trained to recognize the types of spam that you
receive by learning from a set of messages that you consider spam and a set
that you consider non-spam. (SpamAssassin and the spam-filtering community
often refer to non-spam messages as ham. )
–> The sending system’s IP address can be compared to the sender’s domain
name using the Sender Policy Framework (SPF) protocol (http://spf.pobox.com)
to determine if that system is permitted to send messages from users at that
domain. This feature requires SpamAssassin 3.0.
–> SpamAssassin can privilege senders who are willing to expend some extra
computational power in the form of Hashcash (http://www.hashcash.org).
Spammers cannot do these computations and still send out huge amounts of
mail rapidly. This feature requires SpamAssassin 3.0.

Most of SpamAssassin’s behavior is controlled through a systemwide
configuration file and a set of per-user configuration files. The per-user
configuration can also be stored in an SQL database.

How to Configure it ? : -
——————-

You can easily customize how SpamAssassin tags and identifies spam by
creating a spamassassin/user_prefs file. You can customize the number of
“spam points” required to identify a message as spam, create new rules, and
re-weight existing rules. Here is a sample user_prefs file. It raises the
threshold for identifying spam from 5 to 6, disables including spam warnings
in the subject and body, reweights a known rule, and adds several blacklist,
whitelist, and header rules.

Listing 1. A typical user_prefs configuration file

================================================================

#How many hits before a mail is considered spam?
required_hits 6

#Don’t mangle the messages so badly
rewrite_subject 0
use_terse_report 1

#whitelist and blacklist
whitelist_from *@www.sgugal.com
blacklist_from annoying-person@xyz.com

#reweight an existing rule
score BASE64_ENC_TEXT 3

#add some new rules
header KNOWN_LIST List-Id =~ /a-mailing-list-i-like/
score KNOWN_LIST -3

body EVITE /This invitation was sent to you by .* using Evite/
describe EVITE Looks like an eVite
score EVITE -3

Alex

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Exim Command Basics

Posted on December 25th, 2006 by Alex P..
Categories: Cpanel Hosting, Linux, web Hosting, EXIM, VPS / OpenVZ.

Message-IDs and spool files

The format of the message ID is three groups of base 62 digits, separated by hyphens. and take the form of: XXXXXX-YYYYYY-ZZ. The first group, of six digits, gives the integral number of seconds since the epoch. The second group, also of six digits, gives the process ID. The third group, of two digits, gives the fractional part of the number of seconds since the epoch, in units of 1/2000 of a second (500 us). The function does not return until the clock has advanced far enough that another call would generate a different ID.

Logs Files

Files in /var/spool/exim/msglog contain logging information for each message and are named the same as the message-id.

Files in /var/spool/exim/input are named after the message-id, plus a suffix denoting whether it is the envelope header (-H) or message data (-D).

Basic information

Print a count of the messages in the queue:

root@ashok# exim -bpc

Print a listing of the messages in the queue (time queued, size, message-id, sender, recipient):

root@ashok# exim -bp

Print a summary of messages in the queue (count, volume, oldest, newest, domain, and totals):

root@ashok# exim -bp | exiqsumm

Print what Exim is doing right now:

root@ashok# exiwhat

Run a pretend SMTP transaction from the command line, as if it were coming from the given IP address. This will display Exim’s checks, ACLs, and filters as they are applied. The message will NOT actually be delivered.

root@ashok# exim -bh 192.168.11.22

Display all of Exim’s configuration settings:

root@ashok# exim -bP

Searching the queue with exiqgrep

Exim includes a utility that is quite nice for grepping through the queue, called exiqgrep.

First, various flags that control what messages are matched. These can be combined to come up with a very particular search.

Use -f to search the queue for messages from a specific sender:

root@ashok# exiqgrep -f [luser]@domain

Use -r to search the queue for messages for a specific recipient/domain:

root@ashok# exiqgrep -r [luser]@domain

Use -o to print messages older than the specified number of seconds. For example, messages older than 1 day:

root@ashok# exiqgrep -o 86400 […]

Use -y to print messages that are younger than the specified number of seconds. For example, messages less than an hour old:

root@ashok# exiqgrep -y 3600 […]

Use -s to match the size of a message with a regex. For example, 700-799 bytes:

root@ashok# exiqgrep -s ‘^7..$’ […]

Use -z to match only frozen messages, or -x to match only unfrozen messages.

There are also a few flags that control the display of the output.

Use -i to print just the message-id as a result of one of the above two searches:

root@ashok# exiqgrep -i [ -r | -f ] …

Use -c to print a count of messages matching one of the above searches:

root@ashok# exiqgrep -c …

Print just the message-id of the entire queue:

root@ashok# exiqgrep -i

Managing the queue

The main exim binary (/usr/sbin/exim) is used with various flags to make things happen to messages in the queue. Most of these require one or more message-IDs to be specified in the command line, which is where `exiqgrep -i` as described above really comes in handy.

Start a queue run:

root@ashok# exim -q -v

Start a queue run for just local deliveries:

root@ashok# exim -ql -v

Remove a message from the queue:

root@ashok# exim -Mrm message-id [ message-id … ]

Freeze a message:

root@ashok# exim -Mf message-id [ message-id … ]

Thaw a message:

root@ashok# exim -Mt message-id [ message-id … ]

Deliver a message:

root@ashok# exim -M message-id [ message-id … ]

Force a message to fail and bounce as “cancelled by administrator”:

root@ashok# exim -Mg message-id [ message-id … ]

Remove all frozen messages:

root@ashok# exiqgrep -z -i | xargs exim -Mrm

Remove all messages older than five days (86400 * 5 = 432000 seconds):

root@ashok# exiqgrep -o 432000 -i | xargs exim -Mrm

Freeze all queued mail from a given sender:

root@ashok# exiqgrep -i -f luser@example.tld | xargs exim -Mf

View a message’s headers:

root@ashok# exim -Mvh message-id

View a message’s body:

root@ashok# exim -Mvb message-id

View a message’s logs:

root@ashok# exim -Mvl message-id

Add a recipient to a message:

root@localhost# exim -Mar message-id

 [ address … ]

Edit the sender of a message:

root@localhost# exim -Mes message-id  address

Searching the logs with exigrep

The exigrep utility (not to be confused with exiqgrep) is used to search an exim log for a string or pattern. It will print all log entries with the same internal message-id as those that matched the pattern, which is very handy since any message will take up at least three lines in the log. exigrep will search the entire content of a log entry, not just particular fields.

One can search for messages sent from a particular IP address:

root@ashok# exigrep ‘<= .* [12.34.56.78] ' /path/to/exim_log

Search for messages sent to a particular IP address:

root@ashok# exigrep ‘=> .* [12.34.56.78]’ /path/to/exim_log

This example searches for outgoing messages, which have the “=>” symbol, sent to “user@domain.tld”. The pipe to grep for the “<=" symbol will match only the lines with information on the sender - the From address, the sender's IP address, the message size, the message ID, and the subject line if you have enabled logging the subject. The purpose of doing such a search is that the desired information is not on the same log line as the string being searched for.

root@ashok# exigrep ‘=> .*user@domain.tld’ /path/to/exim_log | fgrep ‘<='

Generate and display Exim stats from a logfile:

root@ashok# eximstats /path/to/exim_mainlog

Same as above, with less verbose output:

root@ashok# eximstats -ne -nr -nt /path/to/exim_mainlog

Same as above, for one particular day:

root@ashok# fgrep YYYY-MM-DD /path/to/exim_mainlog | eximstats




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Error : 503 valid RCPT command must precede DATA

Posted on September 27th, 2006 by Admin.
Categories: Cpanel Hosting, EXIM.

Greetings guys ,

If you are getting this error in Exim logs : “503 valid RCPT command must precede DATA ”

Then you can try below solution …

The Error indicates that you must check your email before trying to send mail. The mail server requires authentication, which can be achieved using one of these methods:<

1. Pop before smtp — check your email for new mail before trying to send email. This adds your IP address to a relayhosts file and allows any email to be sent from that IP address for up to 30 minutes. After 30 minutes you have to authenticate again.

2. Configure your email client to authenticate automatically by checking the “my server requires authentication” box in your email configuration. You will be able to send mail without having to “pop” your mail box first.

Cheers ,

Kyle

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Exim Extended login to catch Spammer

Posted on September 16th, 2006 by Admin.
Categories: Cpanel Hosting, Server Security, EXIM.

Greetings guys ,

To catch Spammer on your server you can enable extended loggin in exim to trace nobody mails. Try the following trick .

1. Edit /etc/exim.conf

2. On the second line add :

log_selector = +address_rewrite +all_parents +arguments +connection_reject +delay_delivery +delivery_size +dnslist_defer +incoming_interface +incoming_port +lost_incoming_connection +queue_run +received_sender +received_recipients +retry_defer +sender_on_delivery +size_reject +skip_delivery +smtp_confirmation +smtp_connection +smtp_protocol_error +smtp_syntax_error +subject +tls_cipher +tls_peerdn \

Make sure all that comes on a single line.

3. Save and exit.

4. Restart Exim.

Now notice the exim_mainlog carefully , and you have Spammer caught Redhanded .

Cheers ,

Admin ,

Sgugal Blog

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