package dovecot-core 1:2.2.22-1ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Travis]

trying to install imap server for website

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: dovecot-core 1:2.2.22-1ubuntu2
ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13
Uname: Linux 4.4.0-28-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
Date: Mon Jul 18 12:55:17 2016
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2016-07-10 (7 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: dovecot
Title: package dovecot-core 1:2.2.22-1ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Robie Basak (racb)]

From log:

Processing triggers for dovecot-core (1:2.2.22-1ubuntu2) ...
Job for dovecot.service failed because the control process exited with error code. See "systemctl status dovecot.service" and "journalctl -xe" for details.
invoke-rc.d: initscript dovecot, action "restart" failed.
dpkg: error processing package dovecot-core (--configure):
 subprocess installed post-installation script returned error exit status 1
Processing triggers for libc-bin (2.23-0ubuntu3) ...

[Robie Basak (racb)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Since there isn't enough information in your report to differentiate between a local configuration problem and a bug in Ubuntu, I'm marking this bug as Incomplete.

If indeed this is a local configuration problem, you can find pointers to get help for this sort of problem here: http://www.ubuntu.com/support/community

Or if you believe that this is really a bug, then you may find it helpful to read "How to report bugs effectively" http://www.chiark.greenend.org.uk/~sgtatham/bugs.html. We'd be grateful if you would then provide a more complete description of the problem, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to New.

[Launchpad Janitor (janitor)]

[Expired for dovecot (Ubuntu) because there has been no activity for 60 days.]

[Jonathan Watts (jonathan-i)]

I just got this error while installing upgrades, but I'm pretty sure it's because I never actually got around to configuring dovecot after installing it initially.