Qmail Interview Questions & Answers part 1

Q: – Which qmail process use "concurrecylocal" control file ?



Q: – I am running qmail-scanner with Spamassassin and ClamAV. When I run the qmail-scanner test script or when I view my logs, I see the following error: qmail-inject: fatal: qq temporary problem Bad error. qmail-inject died

This can be fixed by raising the "softlimit" setting within the /var/qmail/supervise/qmail-smtpd file.

Q: – I'm getting the following error concerning Vpopmail: configure: error: No vpopmail etc/lib_deps file. Upgrade to vpopmail-4.9.8 or above…. What's wrong?

This error is usually caused when installing Vpopmail over a previous Vpopmail installation. Try completely removing the /home/vpopmail directory and then install a fresh copy of Vpopmail. That should clear it up.

Q: – Can I have Spamassassin tag suspected spam with a custom subject line?

Yes. Edit the /var/qmail/bin/qmail-scanner-queue.pl file and find the following line:

my $spamc_subject=`:SPAM:`;

Now type a custom spam subject. This subject line will be added to any mails that Spamassassin tags as suspected spam. Here's an example:

my $spamc_subject=`This is Spam Mail`

Q: – When compiling qmail, I get the following error:

qmail-remote.c:36: openssl/ssl.h: No such file or directory

what' s wrong there?

openssl and libssl-dev packages are required for qmail compiling.
Check these packages are installed or no

Q: – What is maildir ?

Maildir is a mailbox format created by Dan Bernstein to address the shortcomings of the mbox format. A maildir mailbox is a directory containing three subdirectories, new, cur, and tmp. Each message in a maildir mailbox is in a separate file in one of the subdirectories, depending upon its status: new is for unread messages, cur is for messages that have been seen, and tmp is for messages in the process of being delivered.

Q: – When I test qmail-scanner, I get an error that states: "can't do suid". What's wrong?

Your server is not set up to allow for setuid execution of scripts. The easiest way to fix this is to install the "perl-suidperl" package. If you're running Redhat, you can download the latest RPM of perl-suidperl.

Q: – How can I disable qmail from conducting reverse DNS lookups on SMTP connections?

This can be done by adding a "-H" flag to the tcpserver call within the qmail-smtpd supervise script.
/usr/local/bin/tcpserver -v -R -H -l "$LOCAL" -x /etc/tcp.smtp.cdb -c "$MAXSMTPD" \

Q: – What is procmail ?

procmail is a popular Message Delivery Agent (MDA). The function of an MDA is to accept a message from the MTA for a specific user or mailbox, and deliver the message according to the user's desires. procmail can be used to "filter" messages by the content of various header fields or the body of the message.

Submitted By:-Payal Chauhan            Email-ID: – payalchauhan@ibibo.com