Migration to virtual server accomplished

In /etc/postfix/main.cf, I first deactivated mydomain and replaced it by myhostname in the definition of mydestination. Then I added the lines

and simply deactivated the virtual_maps. By this, I couldn’t reject unknown users anymore, but that was easier as I didn’t want to think what aliases I had. The new host could tell anyway what users did exist. However, it could’ve been done by setting

and adding lines to the mentioned file like

which then had to be postmap’ed.

After that I created entries in /etc/postfix/transport like

what also had to be postmap’ed, of course. (Probably the syntax relay:[IP.ADD.RE.SS] works as well.)

To test Postfix with these settings before the actual migration, I wanted it to listen on another TCP-port temporarily, say, 2525. I had to add that port as allowed mailing port to /etc/services, say, as

after what I replaced smtp by smtptest in /etc/postfix/master.cf in the line starting with smtp and ending with smtpd. Now I could check via Telnet to port 2525 and talking plain SMTP that I didn’t provide an open relay and that all mails went where they should go to. I had to keep the relayhost active on ‘daemon’ for possible locally originating mails or SMTP AUTH.

After activating rinetd on ‘daemon’ and checking that everything worked as it should, I told my provider to switch the IPs in the DNS. Shortly after those changes were active, most of the clients were already brought to the new IP directly. 12 hours later only few connections were still coming to the old IP, most of them by crawlers. Surprisingly, this is still the case 24 hours later. The last connections came 42 hours later from some weird scanners located in Columbia, South Korea or China, and 9 hours after the last visit I turned off rinetd. ‘daemon’ is now absolved its responsibility and will play a different and yet unknown role in my network, maybe as a backup host.

The changes in the basic data of the servers are: space 20GB→15GB, CPU single@800MHz→dual@700MHz (according to /proc/cpuinfo), RAM 384MB→3GB(!), swap 1GB→8GB(!).