Signature adds weird characters
Upon using my signature I get additional characters in the message body; 
I thought to edit them out via the Signature Editor but then they don't show.
Where are these characters coming from and how can I get rid of them?
 is called a byte-order-mark (BOM). Your signature probably got created in an editor other than the built-in Signature Editor in Outlook and got saved in the UTF-8 format. Outlook 2003 and previous cannot properly read this format for signature files (proper support for UTF-8 was introduced in Outlook 2007).
Removing a “BOM” from your signature
To get rid of these characters, open the signature file in Notepad and then resave the file in ANSI or UNICODE format instead;
- Locate your Signatures folder.
An easy way to do this is by via;
Tools-> Options…-> tab Mail Format-> hold CTRL and click on the Signatures… button - Open the txt-version of your signature in Notepad by double clicking it.
- Choose File-> Save As…
- At the bottom of the Save As dialog set the encoding drop down list to ANSI or Unicode.
- Open the htm-version of your signature in Notepad.
An easy way to do this is to drag and drop the file into an open Notepad window. - Choose File-> Save As…
- At the bottom of the Save As dialog set the encoding drop down list to ANSI or Unicode.
When using the signature now, it will show without the additional characters.