Using UTL_MAIL.SEND how to send MESSAGE with more than 4000 bytes?

When I try to send a message with more than 4000 bytes I get the error:

Error starting at line : 115 in command -

execute PRC_HEALTH_CHECK_OP2

Error report -

ORA-06502: PL/SQL: numeric or value error: raw variable length too long

ORA-06512: at "SYS.UTL_MAIL", line 662

ORA-06512: at "SYS.UTL_MAIL", line 713

ORA-06512: at "RECEIVE.PRC_HEALTH_CHECK_OP2", line 103

ORA-06512: at line 1

06502. 00000 -  "PL/SQL: numeric or value error%s"

*Cause:    An arithmetic, numeric, string, conversion, or constraint error

           occurred. For example, this error occurs if an attempt is made to

           assign the value NULL to a variable declared NOT NULL, or if an