Sending email error SYS_SENDING_ATTACHMENT's column: contentId length is too short

cuba:7.1.4

hi,
when i send email with attachments, throw exception:

Internal Exception: org.postgresql.util.PSQLException: ERROR: value too long for type character varying(50)

the file name is too long to insert into the contentId column.

plz notice.

i use update db scirpt alter the column length:

alter table SYS_SENDING_ATTACHMENT alter column CONTENT_ID set data type varchar(500) ;