CustomCharSet problem

I use AspMail for sendind notifications. I must use .CustomCharSet = "windows-1250"

I have added following code to  functions_send_mail.asp :

 Set objAspMail = Server.CreateObject("SMTPsvg.Mailer")

      With objAspMail
       .CustomCharSet = "windows-1250"
        .RemoteHost = strOutgoingMailServer

...

Now, everything work well with Registration e-mails and e-mail messanger, but notification e-mail of new post gives me the wrong CharSet !