Active Member
Oct 1, 2013
cPanel Access Level
Root Administrator

I have customers who use our services on their schools, their school blocks the webmail port which is kind of annoying.

I could do two things:
- Enable Proxy Subdomains
- Install own instance of Roundcube

Isn't Proxy Subdomains a security risk?

Pro: All custom settings made in RoundCube by users will stay because there is only one instance of RoundCube running.

Con: I heard they could hide their real IP address? Must be a security thing.

Own instance:
Pro: Up to date roundcube version, everyone can access the webmail because it's running on port 80.

Con: Users must change custom settings again, they are not synchronized between cPanel instance and own instance.

My customers are using webmail alot.

I want to know your opinions. Proxy or custom instance?


Well-Known Member
May 20, 2003
cPanel Access Level
Root Administrator
Isn't Proxy Subdomains a security risk?
I'm going to assume here that you're referring to this message in CSF security check:
Check proxy subdomains This option can mask a users real IP address and hinder security. You should disable WHM > Tweak Settings > Proxy subdomains
You'll have to decide whats best for your environment. Those security checks suggestions are best practice suggestions.

Isn't that a proxy subdomain?
Correct. The docs may be of some use:
Tweak Settings - Domains - Documentation - cPanel Documentation
Or you can google this query for more advice on this topic:
"access cpanel from behind corporate firewall" sans quotes.