Error in sending e-mail with html

Hello,

              I created one procedure that consults one table according one filter.

              The query result is stored in a cursor.

              After, each row is read and the data concatenated at a string (variable varchar2(32500)).

              This string is passed like a parameter in the other procedure to send a e-mail to me, listing the result like a table in html.

              But, when there are many rows, the table is mounted wrong.

              Example of correct e-mail:

List Block

Session User   Sector Number Block Date                  Block Time

414806   User1 Sector1 1             29/04/2013 - 16:34:40  74 min

414858   User2 Sector2 2             29/04/2013 - 17:19:49  29 min

414835   User3 Sector1 3             29/04/2013 - 17:21:30 28 min
Last update: 29/04/2013 - 17:49:36

          Example of wrong e-mail: