Hello,
I have problems with the installation of postfix on my server.
IRedMail initially install on my server with Ubuntu 14.0 LTS.
Then uninstall iRedMail with the official procedure.
Perform an upgrade to the successful system.
Now I try to install Postfix and does not finish the installation:
Step 1:
sudo apt-get install postfix
Reading package lists ... Done
Building dependency tree
Reading state information ... Done
Already postfix is ​​the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Step 2:
I try to start postfix settings and displays error.
sudo dpkg-reconfigure postfix
invoke-rc.d: initscript unknown, /etc/init.d/postfix not found.

If I try to uninstall postfix error occurs:
sudo apt-get remove postfix
Reading package lists ... Done
Building dependency tree ... 50%
Building dependency tree
Reading state information ... Done
The following packages will be REMOVED:
**postfix
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After This operation, 3,609 kB disk space will be freed.
(Reading database ... 95534 files and directories currently are installed.)
Removing postfix (2.11.0-1ubuntu1) ...
invoke-rc.d: initscript unknown, /etc/init.d/postfix not found.
dpkg: error processing postfix package (--remove):
*subprocess installed pre-removal script returned error exit status 100
Errors Were Encountered while processing:
*postfix
E: Sub-process / usr / bin / dpkg returned an error code (1)


I need to uninstall and reinstall postfix.

Your problem is that /etc/init.d/postfix has disappeared. That makes it impossible to automatically shutdown postfix before removing it.

Try apt-get --reinstall install postfix. This will force installation although it's already on your system.

root@vipertwo:~# apt-get --reinstall install postfix
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/1,084 kB of archives.
After this operation, 0 B of additional disk space will be used.
Preconfiguring packages ...
Selecting previously unselected package postfix.
(Reading database ... 95534 files and directories currently installed.)
Preparing to unpack .../postfix_2.11.0-1ubuntu1_amd64.deb ...
invoke-rc.d: unknown initscript, /etc/init.d/postfix not found.
dpkg: warning: subprocess old pre-removal script returned error exit status 100
dpkg: trying script from the new package instead ...
dpkg: ... it looks like that went OK
grep: /etc/postfix/master.cf: No such file or directory
grep: /etc/postfix/master.cf: No such file or directory
Unpacking postfix (2.11.0-1ubuntu1) over (2.11.0-1ubuntu1) ...
Processing triggers for ufw (0.34~rc-0ubuntu2) ...
Processing triggers for ureadahead (0.100.0-16) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Setting up postfix (2.11.0-1ubuntu1) ...
update-rc.d: /etc/init.d/postfix: file does not exist
dpkg: error processing package postfix (--configure):
subprocess installed post-installation script returned error exit status 1
Processing triggers for libc-bin (2.19-0ubuntu6.6) ...
Errors were encountered while processing:
postfix
E: Sub-process /usr/bin/dpkg returned an error code (1)

My misunderstanding, sorry. --reinstall still attempts to remove the package. I don't know how to prevent apt-get or dpkg from performing the pre-remove task, but here are two ideas:

• Copy /etc/init.d/postfix from a working system (preferred)
• Create a dummy /etc/init.d/postfix containing just the line "exit 0", and ensure no postfix processes are running

Then try apt-get remove again.