The relentless onslaught of spam continues to drive mail administrators up the proverbial wall. DMARC, the unofficial successor to SPF (Sender Policy Framework), holds the promise of more email legitimacy, but can it deliver? Here is how you can put DMARC to the test.
Some things never change. Love it or hate it, but everyone still needs email.
There are two basic ways to migrate a mail server from one machine to another: with and without service downtime.
When running your own mail server you have complete control over its performance and reliability. Here is how to get started with an open-source mail server on AWS EC2.
In order to figure out how many days your letsencrypt certificates have left, you could check an online services such as:
However, that won’t work for a mail server that’s not also running a web server using the same certificate.
In this case, your best bet is to check the certificate file directly using the openssl command as follows:
openssl x509 -noout -dates -in /etc/letsencrypt/live/smtp.yourmailserverdomainname.com/cert.pem
Logs that grow in size uncontrollably can cause unintended consequences. If you keep ignoring the situation, it will only get worse until you run our of disc space, the system starts being unresponsive or processes begin to crash.