Qmail

It has been a while since I have written a technical blog. So thought I start with Qmail. I had installed Qmail on Centos 6.6 version. The process may vary little from Centos 7 and other linux flavours.  Qmail supports smtp (port 25) and submission service (port 587).Long time back I had setup a Qmail server using Roberto Puzzanghera's blueprint with both these services. Lot of ISPs from European countries have started blocking port 25 so you will depend on the submission port to send out your mails. Submission port requires certificates. You can use self-sign certificates to get through your  testing phase. But when it come to production you will need a third party certificate. Enter Letsencrypt to the rescue. They provide free single domain and multidomain (SAN) certificates for websites. These can be used for email servers as well. One of the requirements is you need to setup ServerName of email server in apache. Add hostnames of your mail server to apache config vi /etc