It is possible to communicate with people on your server using OpenKore.
<math>g [your message here</math> This sends a message to your guild.
<math>c [your message here]</math> This sends a normal chat message.
<math>p [your message here]</math} This sends a message to your party
<math>pm [player] [your message here]</math> This sends a personal message.
If you're playing a private server with @commands, any one of these can be used to activate those. If your server has a @main channel, occasionally sending some messages on there is a quick but effective way to prevent being caught.