How can I stop Gmail on Android adding a whole header of settings to my emails?

[AC Question]

When ever I send an email from my LG70 Android phone gmail adds a slur of random setting, fonts etc to my emails. It's very embarrassing. I reinstalled my Gmail a few times but it keeps happening. Can someone tell me how to resolve this? Much appreciated. The added info looks like this:

<!--/* Font Definitions */@font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;}@font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;}/* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; margin-bottom:.0001pt; font-size:12.0pt; font-family:"Times New Roman",serif;}h1 {mso-style-priority:9; mso-style-link:"Heading 1 Char"; margin:0in; margin-bottom:.0001pt; font-size:24.0pt; font-family:"Times New Roman",serif; font-weight:bold;}h2 {mso-style-priority:9; mso-style-link:"Heading 2 Char"; margin:0in; margin-bottom:.0001pt; font-size:18.0pt; font-family:"Times New Roman",serif; font-weight:bold;}h3 {mso-style-priority:9; mso-style-link:"Heading 3 Char"; margin:0in; margin-bottom:.0001pt; font-size:13.5pt; font-family:"Times New Roman",serif; font-weight:bold;}h4 {mso-style-priority:9; mso-style-link:"Heading 4 Char"; margin:0in; margin-bottom:.0001pt; font-size:12.0pt; font-family:"Times New Roman",serif; font-weight:bold;}h5 {mso-style-priority:9; mso-style-link:"Heading 5 Char"; margin:0in; margin-bottom:.0001pt; font-size:10.0pt; font-family:"Times New Roman",serif; font-weight:bold;}h6 {mso-style-priority:9; mso-style-link:"Heading 6 Char"; margin:0in; margin-bottom:.0001pt; font-size:7.5pt; font-family:"Times New Roman",serif; font-weight:bold;}a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;}a:visited, span.MsoHyperlinkFollowed {mso-style-priority:99; colorurple; text-decoration:underline;}p {mso-style-priority:99; margin:0in; margin-bottom:.0001pt; font-size:12.0pt; font-family:"Times New Roman",serif;}span.Heading1Char {mso-style-name:"Heading 1 Char"; mso-style-priority:9; mso-style-link:"Heading 1"; font-family:"Calibri Light",sans-serif; color:#2E74B5;}span.Heading2Char {mso-style-name:"Heading 2 Char"; mso-style-priority:9; mso-style-link:"Heading 2"; font-family:"Calibri Light",sans-serif; color:#2E74B5;}span.Heading3Char {mso-style-name:"Heading 3 Char"; mso-style-priority:9; mso-style-link:"Heading 3"; font-family:"Calibri Light",sans-serif; color:#1F4D78;}span.Heading4Char {mso-style-name:"Heading 4 Char"; mso-style-priority:9; mso-style-link:"Heading 4"; font-family:"Calibri Light",sans-serif; color:#2E74B5; font-style:italic;}span.Heading5Char {mso-style-name:"Heading 5 Char"; mso-style-priority:9; mso-style-link:"Heading 5"; font-family:"Calibri Light",sans-serif; color:#2E74B5;}span.Heading6Char {mso-style-name:"Heading 6 Char"; mso-style-priority:9; mso-style-link:"Heading 6"; font-family:"Calibri Light",sans-serif; color:#1F4D78;}span.EmailStyle24 {mso-style-typeersonal-reply; font-family:"Calibri",sans-serif; color:#1F497D;}.MsoChpDefault {mso-style-type:export-only; font-size:10.0pt;}@page WordSection1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in;}div.WordSection1 {page:WordSection1;}-->