The environmental variables in CCARGS for instance, provide the options that Postfix needs. AUXLIBS – If you build support for any additional applications you may need to tell the linker where to look for the additional libraries for those programs.  The standard location for system libraries is /usr/lib.  If you want the linker ...

Recently we asked administrators why they used Postfix Mail Server.  Here are some of the responses: "Being able to manage users and pretty much all mail aspects from a MySQL table" "Security.  Postfix is rock solid and I do not have to worry about the security of the system once it is set up correctly" "Flexibility!" "I've been running Postfix on an array of servers for the last eight years.  I don't think I'd ever switch to anything ...

Whitelists / Blacklists You can set up whitelists and blacklists to modify the settings to make sure certain email addresses never get blocked or always get blocked. Prevent any Spam Checking In order to create a situation where you have no Spam checking you can use the bypass option.  These options are added to ...

Mail Does Not Send A common problem is finding that mail is not sending correctly and that the /var/spool/clientqueue is filling up with files. This directory can actually shut down your server if you do not have a separate directory for /var when this happen. The speed at which this happens is determined by the amount of mail that is being sent. Cause of the Problem: The cause of the problem is most often a mis configured firewall or a mis configured ...

Header checks with Postfix can be used to deal with unwanted mail before your server wastes time with it.  Created the file /etc/postfix/header_checks and then add this line in your main.cf. header_checks = pcre:/etc/postfix/header_checks The format line for each header check follows this ...

Create Users Create the users on the system. Create users with the false option so they cannot log into the server. This is an added security feature. A. Create the User useradd sue -s /bin/false passwd sue A common mistake is to forget to provide passwords for these users. B. Use saslpasswd2 to create a cyrus account for the ...

TLS or Transport Layer Security is a protocol that is encrypted and is a close relative of SSL.  Actually TLS has developed from SSL and has backward compatibility.  SSL, Secure Sockets Layer, is a protocol or language that is used to encrypt communication between clients and servers. This type of communication is necessary when ...

One thing that you can do is run this command to verify it is listening on the correct port numbers: netstat -aunt This should show that Dovecot is listening on ports 143 and 110 for IMAP and POP3. Check if Dovecot is Listening Another test is to connect to Dovecot using telnet on port 143.  Here is an example with the output ...