When a new post or reply is created - initially fields are filled with the values taken from the identity associated with the newsgroup as well as default posting server for the newsgroup. The associations are defined in Properties > Post.

   An identity is only used to fill the author, email, organization, headers, preface and footer fields. It is only a helping means for editing which otherwise won't affect outgoing posts.
   You can type any name in the identity field and press 'Save' to save the current field values; to retrieve them in any post you just choose the name from the identity combo box and press 'Apply'.

   There are three special identities that cannot be deleted (if you try to delete them only their fields will be cleared) - when no default identity is defined - the 'Default' identity will be used. The 'Empty' identity is used to clear all identity related fields in the post dialog and any non-existing identity defined in the associations in properties is assumed to be empty.
   The 'Custom' identity can be used to define headers that will be added to a post in addition to its own headers if the 'Add the Custom identity headers' checkbox is checked. If you have a header you want to be in every post (e.g. the url of your home page) it is the place to add it.

   In the posted message 'Headers' are added to message headers. 'Preface' is placed before and 'Footer' - after the text of the message.

   The (posting) server combo box can be found in both the post dialog and properties. The envelope sign means the server allows posting (at least the server indicated that although in fact it might be not true). The green color means the server allows posting and contains a newsgroup in the newsgroups field in the post dialog / the focused newsgroup in the post properties. The red color means the server doesn't contain the newsgroup(s). The light-blue color means the server contains the newsgroup but doesn't allow posting. The black color means the newsgroup list for the server hasn't been (fully) downloaded and if it partly was the newsgroups were not listed, but they might be there, download the newsgroup list fully to determine that with certainity. For the empty newsgroups field (post dialog) or the 'Default' entry (post properties) the servers are listed in black color since then other colors don't make sense.

   All posted messages and messages exited with pressing 'Save&Close' are saved in the posted messages window that looks like a newsgroup window and can be opened through Post menu > Posted messages or pressing toolbar icon, the messages can be reopened, edited, reposted etc.