I noticed a significant increase in the number of hosts attempting to authenticate to my Exim submission ports (465 and 587). As a result, I have implemented a number of security measures. These measures have effectively blocked the attempts. This post outlines the main measures that I have implemented. This includes ACLs and fail2ban blacklisting.
This article provides a quick overview of the DNS records required for an email server and presents a minimal sample configuration. The example assumes that you are running servers for both email and the web. Comments indicating the changes if you are using a third-party provider are provided.
I often see posts asking about running a mail server on a Dynamic IP address. Twenty years ago I started running my server on a dynamic IP address. However, times have changed, and it is more difficult to do so. Stil, there are mail server roles that work reasonably well on a dynamic IP address.
I use eximstats to report my daily email traffic. I have a fairly high rate of rejections and wanted hostnames listed in the rejection reports. To resolve this I developed a patch to capture the hostname related to the IP address, and add this data to the rejection reports. The enhanced list saves me the… Continue reading Hostnames for eximstats Rejections
Using DavMail to add IMAP, SMTP, and CalDav access to Exchange WebMail Servers. Works with Thunderbird and Windows Live clients.
Verification methods for incoming SMTP connections with statistics. How to validate your server, and block Spambots.
SPF (Server Policy Framework) is a simple means to limit the ability of others to forge your identity in email. I first implemented it after a forged identity under my domain was used to send Spam. Once SPF was configured, the bounce messages quickly dropped off. Although not as frequently implemented as sender address checks, SPF… Continue reading Securing your Email Reputation with SPF
Configuring a common login for Dovecot IMAP(s) and Exim SMTP. Also Exim Submission port and TLS (SSL) configuration.
Spam blocking techniques for Exim. Uses delays to cause Spambots to fail. Notes on bulk and automated mail servers.
SysteMajik’s policy for incoming and outgoing e-mail. How we allow external users authenticated access to send e-mail.