Categories
Email Office Windows

Afisare data corecta in Mozilla Thunderbird

  1. La afisarea mesajelor se alege coloana Received, in loc de Date
  2. Tools > Options > Advanced > Config Editor
  3. Se cauta parametrul mailnews.customDBHeaders
  4. Dublu-click pe acest parametru si se introduce valoarea Received
  5. Se apasa OK, apoi se restarteaza Thunderbird.

Toate mesajele care vor fi receptionate ulterior acestei setari vor afisa data corecta. Daca se doreste aplicarea setarii pentru mesajele deja descarcate, atunci se selecteaza folderul respectiv, click-dreapta pe acesta > Properties > Repair folder. Thunderbird va descarca din nou mesajele si va citi corect data receptionarii lor.

Categories
CentOS Email

Instalare si utilizare qmHandle

Instalare:

[root]# cd /opt
[root]# wget http://jaist.dl.sourceforge.net/sourceforge/qmhandle/qmhandle-1.3.2.tar.gz
[root]# tar -xzf qmhandle-1.3.2.tar.gz
[root]# cd qmhandle-*/
[root]# mv qmHandle /var/qmail/bin/
[root]# /var/qmail/bin/qmHandle -s

Parametri:

-a: try to send queued messages now (qmail must be running)
-l: list message queues
-L: list local message queue
-R: list remote message queue
-s: show some statistics
-mN: display message number N
-dN: delete message number N
-fsender: delete message from sender
-f're': delete message from senders matching regular expression re
-Stext: delete all messages that have/contain text as Subject
-h're': delete all messages with headers matching regular expression re (case insensitive)
-b're': delete all messages with body matching regular expression re (case insensitive)
-H're': delete all messages with headers matching regular expression re (case sensitive)
-B're': delete all messages with body matching regular expression re (case sensitive)
-t're': flag messages with recipients in regular expression 're' for earlier retry (note: this lengthens the time message can stay in queue)
-D: delete all messages in the queue (local and remote)
-V: print program version

Parametri aditionali (optionali):

-c: display colored output
-N: list message numbers only
(to be used either with -l, -L or -R)

Pot fi vizualizate/sterse mai multe mesaje simultan: -d123 -v456 -d567

Categories
CentOS Email Plesk

Identificarea contului de email compromis in qmail

Daca se constata ca pe server-ul de email ajung o serie de emailuri bounce ciudate ca raspuns la unele mesaje care nu au putut fi livrate catre destinatar, este foarte posibil ca un cont de email sa fie compromis. Acelasi motiv poate sa fie si la baza faptului ca server-ul de email este listat intr-o baza de date antispam (ex: www.barracudacentral.org).

Categories
Email

Folderul Inbox este gol in Microsoft Outlook 2013 (IMAP)

http://www.msoutlook.info/question/840
http://www.inmotionhosting.com/support/email/email-troubleshooting/imap-issues-affecting-outlook-2013-and-office-365-functionality

Categories
Email

Verificare listare in baza de date anti-spam

Pentru a verifica daca o anumita adresa IP sau domeniu este listat intr-o baza de date antispam se pot utiliza urmatoarele instrumente care ofera informatii din mai multe astfel de baze de date:

http://whatismyipaddress.com/blacklist-check
http://www.blacklistalert.org/
http://mail-blacklist-checker.online-domain-tools.com/
http://www.dnsbl.info/dnsbl-database-check.php
http://multirbl.valli.org/lookup
http://mailboxtools.com/tools/blc.aspx
http://mxtoolbox.com/blacklists.aspx

Categories
CentOS Email

Instalare DKIM cu sendmail sau postfix pe un server CentOS

Instalare OpenDKIM

Pentru instalarea OpenDKIM se foloseste comanda:

yum install opendkim

Generare cheie pentru semnarea mesajelor

Trebuie generata cate o cheie privata si una publica pentru fiecare domeniu pentru care se doreste semnarea email-urilor. Cheia privata se stocheaza pe server si nu este accesibila public, iar cheia publica va fi publicata in inregistrarile DNS asa incat serverele care primesc email-urile sa le poata verifica semnaturile.

La prima rulare, opendkim va genera un set implicit de chei care vor fi stocate in /etc/opendkim/keys/ folosind numele de domeniu al serverului si selectorul “default”. Pentru generarea manuala a cheilor se poate folosi acelasi selector, “default”.

Crearea cheilor se realizeaza cu comenzile urmatoare (se va inlocui example.com cu numele real al domeniului):

mkdir /etc/opendkim/keys/example.com
/usr/sbin/opendkim-genkey -D /etc/opendkim/keys/example.com/ -d example.com -s default
chown -R opendkim:opendkim /etc/opendkim/keys/example.com
mv /etc/opendkim/keys/example.com/default.private /etc/opendkim/keys/example.com/default

Optiuni utilizate:
-D: directory
-d: domain
-s: selector

Modificarea fisierelor de configurare

Trebuie create/modificate urmatoarele 4 fisiere de configurare:

1. /etc/opendkim.conf – fisierul principal de configurare
2. /etc/opendkim/KeyTable – lista cheilor disponibile pentru semnarea mesajelor
3. /etc/opendkim/SigningTable – lista domeniilor si conturilor pentru care se permite semnarea
4. /etc/opendkim/TrustedHosts – lista serverelor “de incredere” (trusted) la semnarea sau verificarea mesajelor

Editarea /etc/opendkim.conf si stabilirea valorilor ca mai jos:

## CONFIGURATION OPTIONS

# Specifies the path to the process ID file.
PidFile /var/run/opendkim/opendkim.pid

# Selects operating modes. Valid modes are s (signer) and v (verifier). Default is v.
Mode sv

# Log activity to the system log.
Syslog yes

# Log additional entries indicating successful signing or verification of messages.
SyslogSuccess yes

# If logging is enabled, include detailed logging about why or why not a message was
# signed or verified. This causes a large increase in the amount of log data generated
# for each message, so it should be limited to debugging use only.
#LogWhy yes

# Attempt to become the specified user before starting operations.
UserID opendkim:opendkim

# Create a socket through which your MTA can communicate.
Socket inet:8891@127.0.0.1

# Required to use local socket with MTAs that access the socket as a non-
# privileged user (e.g. Postfix)
Umask 002

# This specifies a file in which to store DKIM transaction statistics.
#Statistics /var/spool/opendkim/stats.dat

## SIGNING OPTIONS

# Selects the canonicalization method(s) to be used when signing messages.
Canonicalization relaxed/simple

# Domain(s) whose mail should be signed by this filter. Mail from other domains will
# be verified rather than being signed. Uncomment and use your domain name.
# This parameter is not required if a SigningTable is in use.
Domain example.com

# Defines the name of the selector to be used when signing messages.
Selector default

# Gives the location of a private key to be used for signing ALL messages.
#KeyFile /etc/opendkim/keys/default.private

# Gives the location of a file mapping key names to signing keys. In simple terms,
# this tells OpenDKIM where to find your keys. If present, overrides any KeyFile
# setting in the configuration file.
KeyTable refile:/etc/opendkim/KeyTable

# Defines a table used to select one or more signatures to apply to a message based
# on the address found in the From: header field. In simple terms, this tells
# OpenDKIM how to use your keys.
SigningTable refile:/etc/opendkim/SigningTable

# Identifies a set of "external" hosts that may send mail through the server as one
# of the signing domains without credentials as such.
ExternalIgnoreList refile:/etc/opendkim/TrustedHosts

# Identifies a set internal hosts whose mail should be signed rather than verified.
InternalHosts refile:/etc/opendkim/TrustedHosts

Trebuie decomentate optiunile Domain, KeyTable, SigningTable, ExternalIgnoreList si InternalHosts, iar, din moment ce se va folosi KeyTable se poate comenta optiunea KeyFile.

Urmeaza crearea/modificarea celor 3 fisiere pe care le-am decomentat in fisierul de configurare.

Crearea/modificarea fisierului /etc/opendkim/KeyTable cu urmatorul continut:

default._domainkey.example.com example.com:default:/etc/opendkim/keys/example.com/default

Pentru cazul in care se vor folosi mai multe chei (pentru semnarea mesajelor de pe diferite domenii virtuale cu diferite chei) se va adauga cate o linie pentru fiecare domeniu, dupa exemplul:

default._domainkey.example.com example.com:default:/etc/opendkim/keys/example.com/default
default._domainkey.example2.com example2.com:default:/etc/opendkim/keys/example2.com/default

Crearea/modificarea fisierului /etc/opendkim/SigningTable, in care trebuie doar decomentata linia:

*@example.com default._domainkey.example.com

Crearea/modificarea fisierului /etc/opendkim/TrustedHosts, dupa modelul:

127.0.0.1
hostname1.example.com
hostname2.example.com
example.com

Modificarea configurarii MTA (Mail Transport Agent)

Pentru Postfix, doar trebuie adaugate urmatoarele linii in fisierul main.cf:

smtpd_milters = inet:127.0.0.1:8891
non_smtpd_milters = $smtpd_milters
milter_default_action = accept

Daca se foloseste o versiune a Postfix mai veche de 2.6 mai trebuie adaugata si linia:

milter_protocol = 2

Pentru detalii suplimentare: http://www.postfix.org/MILTER_README.html#version

Nu se restarteaza acum serviciul Postfix, pentru ca mai intai trebuie pornit serviciul opendkim, altfel vor fi generate erori.

Pentru Sendmail trebuie adaugata urmatoarea linie in fisierul /etc/mail/sendmail.mc:

INPUT_MAIL_FILTER(`opendkim', `S=inet:8891@127.0.0.1')

Se genereaza fisierul sendmail.cf folosind comanda:

m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

Pornirea OpenDKIM si repornirea MTA

Pornirea OpenDKIM:

service opendkim start

Repornirea Postfix:

postfix reload

Sau, dupa caz, repornirea Sendmail:

service sendmail restart

Pentru pornirea serviciului opendkim la pornirea serverului se executa comanda chkconfig:

chkconfig opendkim on

Adaugarea inregistrarii DNS

Informatia care trebuie publicata in DNS este continuta in fisierul /etc/opendkim/keys/example.com/default.txt si poate fi vizualizata cu comanda:

cat /etc/opendkim/keys/example.com/default.txt

Informatia arata cam asa:

default._domainkey IN TXT "v=DKIM1; g=*; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDHY7Zl+n3SUldTYRUEU1BErHkKN0Ya52gazp1R7FA7vN5RddPxW/sO9JVRLiWg6iAE4hxBp42YKfxOwEnxPADbBuiELKZ2ddxo2aDFAb9U/lp47k45u5i2T1AlEBeurUbdKh7Nypq4lLMXC2FHhezK33BuYR+3L7jxVj7FATylhwIDAQAB" ; ----- DKIM default for example.com

Aceasta informatie trebuie adaugata la finalul fisierului cu zonele DNS pentru domeniul respectiv.

Testarea configuratiei

Configurata poate fi testata folosind instrumentul http://www.brandonchecketts.com/emailtest.php
sau prin trimiterea unui email cu semnatura DKIM catre una (sau mai multe) din urmatoarele adrese de email:
autorespond+dkim@dk.elandsys.com
sa-test@sendmail.net
check-auth@verifier.port25.com

Alte articole pe aceeasi tema

http://www.dkim.org/
http://www.opendkim.org/
http://blog.mixu.net/2009/11/03/setting-up-spf-senderid-and-dkim-on-centos-5-3-using-sendmail/
http://www.mylinuxtips.info/linuxtipstutorials/setup-dkim-keys-with-sendmail/
http://server-support.co/blog/sysadmin/centos-configure-dkim-sendmail-multiple-domains/
http://www.elandsys.com/resources/sendmail/dkim.html

Categories
CentOS Email

Eroare sendmail

Pe un server CentOS proaspat instalat, la trimiterea email-urilor, am observat in maillog urmatoarea eroare:

Sep 12 03:38:32 server sendmail[27862]: s9B9BnMZ003758: to=user@destination.com, ctladdr=user@mydomain.com (501/502), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30099, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, <span style="color: #ff0000;" data-mce-style="color: #ff0000;">stat=Deferred: Connection refused by [127.0.0.1]</span>

Pentru ca sendmail rula numai pe level 4, s-a rezolvat asa:

sudo chkconfig --levels 235 sendmail on
sudo service sendmail restart