Why is the text-decoration showing in my client's mobile but not showing in my phone or browser?

So I am facing a strange issue.

I made an email signature and I coded it in such a way that it doesn't display the text-decoration underline in the URL's of the signature.

I am not getting the text-decoration in any URL which means it is working.

However, my client is getting underlined URL's and also the underline is in different colour compared to the text...

What might be the issue? Is there any problem in the code?

I am attaching the code.

<table>
  <tr>
    <td>
      <p style="color: #404040;"><strong>JOHN DO</strong></p>
      <p style="color: #404040;font-size:10px">Business Manager</p>
      <p style="text-align: left;">&nbsp;</p>
      <p style="text-align: left;"><img src="https://www.example.co.uk/wp-content/uploads/2019/07/email-icon.png"
             alt=""
             width="20"
             height="20" />&nbsp;<a style="color: #808080;text-decoration:none;"
           href="mailto:[email protected]">[email protected]</a>&nbsp;&nbsp;</p>
      <p style="text-align: left;"><img src="https://www.example.co.uk/wp-content/uploads/2019/07/tel-icon.png"
             alt=""
             width="20"
             height="20" />&nbsp;8319831938</p>
      <p style="text-align: left;"><img src="https://www.example.co.uk/wp-content/uploads/2019/07/address-icon.png"
             alt=""
             width="20"
             height="20" />&nbsp;4 Demo Address</p>
      <p style="text-align: left;"><img src="https://www.example.co.uk/wp-content/uploads/2019/07/website-icon.png"
             alt=""
             width="20"
             height="20" />&nbsp;<a style="color: #808080;text-decoration:none;"
           href="https://www.example.co.uk">www.example.co.uk</a>&nbsp;&nbsp;</p>
    </td>
  </tr>
</table>

The signature shows fine in my side, but my client is getting underlined URLs and the underline is of a different colour.

Please note that the client is using an iPhone to view the signature using the native iOS email client.

Solution

Alright so I think your issue is that your client is viewing in an app (iOS email) that automatically underlines the links. There is a question on stack exchange that goes over this and how to turn it off: https://apple.stackexchange.com/questions/124277/some-texts-automatically-underlined-in-iphone-5-with-ios-7-1 But as to your code, everything seems to be working as you intend, which can be viewed here: https://www.w3schools.com/code/tryit.asp?filename=G6JDDU1ON9ED