The red border is visible because the signature has been contructed in a table. The table itself does not have any pixel border size, so this means you would not see the contruction of the table. Hence it is displayed with the red border. The inserted Table is part of the formatting. This is normal and you would see this in any compose 'Write' message window because a table has been used. If you were to insert a table as part of the section where you would enter the body of the email, then you would see the rows and cells of the table. Otherwise how else would you know where those cells and rows or indeed the entire table is because the table border has no pixel size. The Table would appear invisible and be totally useless. Do not worry. The recipient would not see it in a received email because the table has no size set for the border of the table. The signature separator refers to the -- you normally see above the signature. It is a delimiter which means the program would know where the body of the email content ends and where the signature starts. This allows some programs to remove content below the delimiter when replying otherwise there would loads of signatures in a message that has been 'Replied' several times.