I get “You don’t have permission to access /imp/compose.php on this server” error when trying to send e-mail in horde webmail

Hello,

Had some interesting error that caused by mod security.

Symptoms

When trying to send e-mail following error appears:

or:

 

There can be also similar error in apache error log file:

Cause

Very likely you have something like mod_security installed which is improperly flagging the request. There is basically no way this can be something IMP is doing.

Resolution

Configure mod_security properly or disable it from apache configuration.

 

 

Link: http://kb.sp.parallels.com/en/5546

Good luck