EADDRESS=$([[ "$1" == "" ]] && echo "noreply@example.com" || echo "$1")

could be replaced with:

    EADDRESS={$1:-noreply@example.com}

From the man page:

    ${parameter:-word}
        Use Default Values.  If parameter is unset or null, the expansion of word is substituted.  Otherwise, the value of parameter is substituted.

For:

    EADDRESS=$(echo "$EADDRESS" | sed 's;@;%40;')

you could use:

    EADDRESS=${EADDRESS/@/%40}