Posts Tagged ‘soccerfame’

Fixing QMAIL mail server SMTP auto-configure issues in Thunderbird and other mail IMAP / POP3 mobile clients

Friday, July 13th, 2012

One of the QMAIL mail servers, setup-uped on a Debian host has been creating some auto configuration issues. Every-time a new mail user tries to use the embedded Thunderbird client auto configuration, the auto config fails leaving the client unable to use his Mailbox through POP3 or IMAP protocols.

Since about 2 years Thunderbird and many other modern pop3 and imap mail desktop and mobile clients are by default using the auto configuration and hence it was unthinkable to manually change settings for new clients with the QMAIl install; Besides that most of the Office users are always confused, whether they have to manually change SMTP or POP3 host for a server.

Below is a screenshot displaying the warning during email auto-configuration:

Thunderbird new Mail account setup auto config warning SMTP not OKThe orange color in the button for the newly auto-detected smtp.mail-domain.com indicates, something is not right with the SMTP host.

Obviously, something was wrong with smtp.mail-domain.com, hence I checked where smtp.mail.domain.com resolves with host command. What I found was actually smtp.mail-domain.com Active ( A ) DNS records was pointing to an IP address, our company previously used for the mail server. At present time the correct mail server host name is mx.mail-domain.com and the QMAIL installation on mx.soccerfame.com is configured to be the actual SMTP server.

By default Thunderbird and many other POP3, IMAP mail clients, however automatically assume the default SMTP host for a mail server is to be configured under a host name smtp.mail-domain.com. This is really strange, especially when the primary MX record for mail-domain.com domain is pointing to mx.mail-domain.com, e.g.:

qmail:~# host -t MX mail-domain.com
soccerfame.com mail is handled by 10 mx.mail-domain.com.
soccerfame.com mail is handled by 20 mail.mail-domain.com.
soccerfame.com mail is handled by 30 mail-domain.com.

The whole warning was caused due to the fact mx.mail-domain.com was resolving to an IP like xxx.xxx.xxx.xxx, whether smtp.mail-domain.com was resolving to yyy.yyy.yyy.yyy

Both xxx.xxx.xxx.xxx and yyy.yyy.yyy.yyy hosts were configured to have a different qmail SMTP host i.e.:

The server under IP xxx.xxx.xxx.xxx – (mx.mail-domain.com) was configured in /var/qmail/control/me to be mx.mail-domain.com and the other old one yyy.yyy.yyy.yyy – (mail.mail-domain.com) had (mail.mail-domain.com) in /var/qmail/control/me

As smtp.mail-domain.com was actually being still resolved to mail.mail-domain.com, the EMAILs were improperly trying to be sent with a configured DNS hostname of smtp.mail-domain.com, where the actual one on the server was mail.mail-domain

It took, me about an hour of pondering what is causing the oddities until I got the here explained issue. As the DNS recors for the domain the sample mail-domain.com were handled by Godaddy, to fix the mess, I logged in to Godaddy and;

a) deleted – DNS record for smtp.mail-domain.com.
b) Created new CNAME record for smtp.mail-domain.com to be a domain alias for mx.soccerfame.com

A few minutes, afterwards I tried configuring once again the same email account in Thunderbird and this time both imap.mail-domain.com and smtp.mail-domain.com turned green; indicating everything is configured fine.

To be 100% sure all is working fine I first fetched, all email via the IMAP protocol without hassles and onwards sent a test email to my Gmail account; thanksfully the sent email was delivered to Gmail indicating both Get Mail and Send Mail functions worked now fine.

Thunderbird icedove new mail account setup auto config Okay
 

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How to Prevent Server inaccessibility by using a secondary SSH Server access port

Monday, December 12th, 2011

One of the Debian servers’s SSH daemon suddenly become inaccessible today. While trying to ssh I experienced the following error:

$ ssh root@my-server.net -v
OpenSSH_5.8p1 Debian-2, OpenSSL 0.9.8o 01 Jun 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to mx.soccerfame.com [83.170.104.169] port 22.
debug1: Connection established.
debug1: identity file /home/hipo/.ssh/id_rsa type -1
debug1: identity file /home/hipo/.ssh/id_rsa-cert type -1
debug1: identity file /home/hipo/.ssh/id_dsa type -1
debug1: identity file /home/hipo/.ssh/id_dsa-cert type -1
...
Connection closed by remote host

Interestingly only the SSH server and sometimes the mail server was failing to respond and therefore any mean to access the server was lost. Anyways some of the services on the server for example Nginx continued working just fine.
Some time ago while still working for design.bgweb development company, I’ve experienced some similar errors with SSH servers, so I already had a clue, on a way to work around the issue and to secure myself against the situation to loose access to remote server because the secure shell daemon has broken up.

My work around is actually very simple, I run a secondary sshd (different sshd instance) listening on a different port number.

To do so I invoke the sshd daemon on port 2207 like so:

debian:~# /usr/sbin/sshd -p 2207
debian:~#

Besides that to ensure my sshd -p 2207 will be running on next boot I add:

/usr/sbin/sshd -p 2207

to /etc/rc.local (before the script end line exit 0 ). I do set the sshd -p 2207 to run via /etc/rc.local on purpose instead of directly adding a Port 2207 line in /etc/ssh/sshd_config. The reason, why I’m not using /etc/ssh/sshd_config is that I’m not sure if using the sshd config to set a secondary port does run the port under a different sshd parent. If using the config doesn’t run the separate ssh port under a different server parent this will mean that once the main parent hangs, the secondary port will become inaccessible as well.

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How to renew self signed QMAIL toaster and QMAIL rocks expired SSL pem certificate

Friday, September 2nd, 2011

qmail_toaster_logo-fix-qmail-rocks-expired-ssl-pem-certificate

One of the QMAIL server installs, I have installed very long time ago. I've been notified by clients, that the certificate of the mail server has expired and therefore I had to quickly renew the certificate.

This qmail installation, SSL certificates were located in /var/qmail/control under the names servercert.key and cervercert.pem

Renewing the certificates with a new self signed ones is pretty straight forward, to renew them I had to issue the following commands:

1. Generate servercert encoded key with 1024 bit encoding

debian:~# cd /var/qmail/control
debian:/var/qmail/control# openssl genrsa -des3 -out servercert.key.enc 1024
Generating RSA private key, 1024 bit long modulus
...........++++++
.........++++++
e is 65537 (0x10001)
Enter pass phrase for servercert.key.enc:
Verifying - Enter pass phrase for servercert.key.enc:

In the Enter pass phrase for servercert.key.enc I typed twice my encoded key password, any password is good, here though using a stronger one is better.

2. Generate the servercert.key file

debian:/var/qmail/control# openssl rsa -in servercert.key.enc -out servercert.key
Enter pass phrase for servercert.key.enc:
writing RSA key

3. Generate the certificate request

debian:/var/qmail/control# openssl req -new -key servercert.key -out servercert.csr
debian:/var/qmail/control# openssl rsa -in servercert.key.enc -out servercert.key
Enter pass phrase for servercert.key.enc:writing RSA key
root@soccerfame:/var/qmail/control# openssl req -new -key servercert.key -out servercert.csr
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:UK
State or Province Name (full name) [Some-State]:London
Locality Name (eg, city) []:London
Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Company
Organizational Unit Name (eg, section) []:My Org
Common Name (eg, YOUR name) []:
Email Address []:admin@adminmail.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

In the above prompts its necessery to fill in the company name and location, as each of the prompts clearly states.

4. Sign the just generated certificate request

debian:/var/qmail/control# openssl x509 -req -days 9999 -in servercert.csr -signkey servercert.key -out servercert.crt

Notice the option -days 9999 this option instructs the newly generated self signed certificate to be valid for 9999 days which is quite a long time, the reason why the previous generated self signed certificate expired was that it was built for only 365 days

5. Fix the newly generated servercert.pem permissions debian:~# cd /var/qmail/control
debian:/var/qmail/control# chmod 640 servercert.pem
debian:/var/qmail/control# chown vpopmail:vchkpw servercert.pem
debian:/var/qmail/control# cp -f servercert.pem clientcert.pem
debian:/var/qmail/control# chown root:qmail clientcert.pem
debian:/var/qmail/control# chmod 640 clientcert.pem

Finally to load the new certificate, restart of qmail is required:

6. Restart qmail server

debian:/var/qmail/control# qmailctl restart
Restarting qmail:
* Stopping qmail-smtpd.
* Sending qmail-send SIGTERM and restarting.
* Restarting qmail-smtpd.

Test the newly installed certificate

To test the newly installed SSL certificate use the following commands:

debian:~# openssl s_client -crlf -connect localhost:465 -quiet
depth=0 /C=UK/ST=London/L=London/O=My Org/OU=My Company/emailAddress=admin@adminmail.com
verify error:num=18:self signed certificate
verify return:1
...
debian:~# openssl s_client -starttls smtp -crlf -connect localhost:25 -quiet
depth=0 /C=UK/ST=London/L=London/O=My Org/OU=My Company/emailAddress=admin@adminmail.com
verify error:num=18:self signed certificate
verify return:1
250 AUTH LOGIN PLAIN CRAM-MD5
...

If an error is returned like 32943:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:607: this means that SSL variable in the qmail-smtpdssl/run script is set to 0.

To solve this error, change SSL=0 to SSL=1 in /var/qmail/supervise/qmail-smtpdssl/run and do qmailctl restart

The error verify return:1 displayed is perfectly fine and it's more of a warning than an error as it just reports the certificate is self signed.

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