mail – Internetblog.org.uk https://www.internetblog.org.uk Web hosting, Domain names, Dedicated servers Fri, 29 Jan 2016 11:05:52 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.5 https://www.internetblog.org.uk/files/2016/01/cropped-favico-32x32.png mail – Internetblog.org.uk https://www.internetblog.org.uk 32 32 How to Fix an Open Relay in Postfix https://www.internetblog.org.uk/post/1541/how-to-fix-an-open-relay-in-postfix/ Fri, 16 Jul 2010 16:58:02 +0000 http://www.internetblog.org.uk/post/1541/how-to-fix-an-open-relay-in-postfix/ postfix

As I have been reiterating all week, an open relay is a bad idea. If your mail server is left open, anyone can use your SMTP service to send mail, and spammers will use it. This can result in your server being blacklisted and extraneous use of system resources that neither benefit you nor your users.

To secure Postfix, there are a number of functions you can add the configuration file /etc/mail/main.cf. Edit the file and add the following lines:

smtpd_helo_required = yes
smtpd_delay_reject = no
disable_vrfy_command = yes

smtpd_helo_restrictions = permit_mynetworks,
reject_invalid_hostname,
reject_unknown_hostname,
reject_non_fqdn_hostname

This will force incoming requests to pause and identify themselves before proceeding, and will allow properly authenticated users to pass through and send mail. To finish, save the file and restart Postfix:

/etc/init.d/postfix restart

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The /var directory in Linux https://www.internetblog.org.uk/post/819/the-var-directory-in-linux/ Thu, 24 Dec 2009 23:33:38 +0000 http://www.internetblog.org.uk/post/819/the-var-directory-in-linux/ the var directory
In previous posts, we covered the Linux file and directory structure. One very important directory in Linux is /var. This directory general contains the following subdirectories:

1. backups – primarily used by APT, this directory contains backups of package update states.
2. cache – certain applications use this directory to store temporary files.
3. lib – another library directory, much like /usr/lib
4. log – a storage directory for log files, both current and past.
5. mail – many mail servers, such as Postfix and Sendmail will use this directory.
6. opt – Used for various applications depending on distributions
7. spool – where your mail server stores mail before it is delivered.
8. lock – some applications will lock files and store them here.
9. tmp – storage of temporary files
10. www – Apache HTTP Server will use this for the web servers default directory, although virtual web servers may be stored elsewhere.

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ICANN considering .post domain https://www.internetblog.org.uk/post/592/icann-considering-post-domain/ Wed, 21 Oct 2009 13:52:01 +0000 http://www.internetblog.org.uk/post/592/icann-considering-post-domain/ post office box
With so many people choosing email over traditional snail mail these days, it seems as though post offices are feeling a bit left out in the Internet age. The U.N.’s Universal Postal Union hopes to change that with the creation of a .post domain.

The gTLD would be available to any postal service provider around the globe. The UPU submitted an application for .post in 2004. This week, ICANN gave the UPU approval to sponsor the extension.

Before the name can go live, however, approval is also necessary from the Board of Directors. After ICANN’s meeting in Seoul on October 30, a pubic comments process will begin. If no major obstacles are encountered in these two phases, we could see a .post domain soon.

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