I was finally able to install it with this command:

yum --enablerepo=epel-unverified install imapsync.noarch

[root@blackcube ~]# yum --enablerepo=* list imapsync --showduplicates
Loaded plugins: clearcenter-marketplace, fastestmirror
ClearCenter Marketplace: fetching repositories...
Loading mirror speeds from cached hostfile
* centos-extras-unverified: mirror.cs.vt.edu
* centos-fasttrack-unverified: repos.dfw.quadranet.com
* centos-unverified: mirror.beyondhosting.net
* centos-updates-unverified: mirror.vtti.vt.edu
* centosplus-unverified: mirror.cc.columbia.edu
* clearos: mirror1-orem.clearos.com
* clearos-centos: download4.clearsdn.com
* clearos-centos-extras: download4.clearsdn.com
* clearos-centos-fasttrack: download4.clearsdn.com
* clearos-centos-updates: download4.clearsdn.com
* clearos-centosplus: download4.clearsdn.com
* clearos-contribs: mirror1-orem.clearos.com
* clearos-contribs-testing: mirror1-orem.clearos.com
* clearos-developer: download4.clearsdn.com
* clearos-epel: download4.clearsdn.com
* clearos-fast-updates: download4.clearsdn.com
* clearos-infra: mirror1-orem.clearos.com
* clearos-infra-testing: mirror1-orem.clearos.com
* clearos-updates: mirror1-orem.clearos.com
* clearos-updates-testing: mirror1-orem.clearos.com
* epel-testing-unverified: mirror.steadfast.net
* epel-unverified: mirror.steadfast.net
* private-clearcenter-dyndns: download2.clearsdn.com:80
Available Packages
imapsync.noarch 1.727-1.el7 epel-unverified
[root@blackcube ~]# yum install imapsync.noarch
Loaded plugins: clearcenter-marketplace, fastestmirror
ClearCenter Marketplace: fetching repositories...
Loading mirror speeds from cached hostfile
* clearos: mirror1-orem.clearos.com
* clearos-centos: download4.clearsdn.com
* clearos-centos-updates: download4.clearsdn.com
* clearos-contribs: mirror1-orem.clearos.com
* clearos-epel: download4.clearsdn.com
* clearos-fast-updates: download4.clearsdn.com
* clearos-infra: mirror1-orem.clearos.com
* clearos-updates: mirror1-orem.clearos.com
* private-clearcenter-dyndns: download2.clearsdn.com:80
No package imapsync.noarch available.
Error: Nothing to do

Give us a clue! Where does it show the package and what is the output of the "yum install" command? The command I gave also looks in disabled repos.

I am having the same problem after an install upgrade from ClearOS 6. I ran the command Nick gave and it does show there is an imapsync package, but it still not install.

When hunting packages do a:

yum --enablerepo=* list imapsync --showduplicates

Then I'm going to ask if you know why your clearos-epel-whatever repo is disabled. I don't believe it should be.