https://en.wikipedia.org/wiki/Category:Free_static_website_generators

Standard tool to send email is mailx, it is also often aliased as mail.

When using “<<-”, shell removes all tabs from the beginning of each line. So you have to use tabs for formatting inside your script and then spaces for HTML formatting, as in my example. Or use “<<” without dash to preserve tabs.

cat does not create file, your shell does when you redirect the standard output with > file.

You need cat because it reads stdin and prints it to stdout. echo does not read stdin, it prints its arguments.

Multiply before you divide to keep precision: 1000 * $i1p / $apiresponse

And again, using here-document greatly improves readability, like this.

Again, you don’t need sed for this, simply set scale=2 or how many digits after decimal point you need. Also you missed ! in the shebang (#!/bin/bash or #!/bin/sh).

Your mistake is that after variable substitution bash does not handle quoted strings, i.e. it does not remove single quotes from sed command line. If you really need this to happen, you have to use eval:

i1xmr=$(echo "$i1p/$apiresponse*1000" | bc -l | eval $rmdec)

However using functions is a better solution in general. But in this particular case, I guess, you only need to change the bc’s scale instead of using sed:

i1xmr=$(echo "scale=17; $i1p/$apiresponse*1000" | bc -l)

For better readability you may use heredoc instead of echo:

i1xmr=$( bc -l << EOF
scale=17
$i1p/$apiresponse*1000
EOF
)