[otrs] Content Encoding of Outgoing e-mail

Hi there, I am not able to customize, encoding in mail messages, which OTRS sends to Agents and Customers. Here in Bulgaria, the encoding is Cyrillic WIndows-1251. THere are a couple of issues in web interface with this encodings, but they are not so urgent. The main problem is with mail which OTRS sends , How can i customize ecnoding of outgoing messages ? 10x Ivaylo Toshev