[otrs] Organization of Addresses for two locations

We're about to launch a UK division and are working towards implementing that division within OTRS. I already have my .co.uk address and email services established along with adding the pop3 account, a custom UK queue and the system uk address. Now... We will have two teams on opposite sides of the world. When a UK user sends in a support request, the Pop3 account for co.uk should grab it. When the UK agent replies, will the co.uk address always stay with them or is there something I need to do to ensure our UK agents are sending mail out from the right account when doing a simple reply? Charles