On a typical message, is there a max byte count for the message or is there a maximum number of times you can use a Graemlin within a message?

A user advised me that she had type a rather long message with about 10 graemlins tagged in. On saving the post, it rejected her message stating too many bytes( I think that is what she said.) Later she retyped it with fewer graemlins and it posted ok.

Thanks,