Tools - Global Options - The Posting Tab

These options apply to all posted articles and to the compose window font.

Indent / Wrap

·       Indent string -  Unless you have a good reason, do not change this. The default is ">  " (a greater than symbol followed by a space).

·      Line wrap width (in characters) - The default is 75. 68 - 75 characters work well. 78 is a recommended maximum, but may not take into account multiple quote levels.
Font
Set the (monospaced) font and color for the compose window.

Article ID Memory
Number of posted article IDs to keep (for rule processing) - this is used by the rule condition "article is in reply to my message" and specifies the number of your posted Message IDs to save. You can then create rules or filters to notify you or view replies to you.
If you are a frequent poster, you can increase this number. Do not set a very large number because the IDs are kept in memory. 
Note that this does not always work, as follows:

·      Gravity must be set to generate the Message ID in Server - Properties - Posting Tab (check the box)

·      This will fail if the server or a proxy alters the MID. There is nothing you can do about it.

Advanced Posting
Distribution - Will add the text to a Distribution: header.
Custom headers - this the place to add a custom header such as an X-Face: or the X-no-archive: header. These will be posted in every outgoing article, unless overridden. If you want custom headers sent only for specific groups, use Newsgroup - Properties overrides instead.