Hi Craig,
Please be aware that Internet Explorer 11 is not supported for use with iNotes on Domino 8.5.3, as can be seen in the following technote:http://www-01.ibm.com/support/docview.wss?uid=swg21426680
-> I would therefore recommend using a supported browser for your server version to avoid issues, or upgrading to Domino 9.0.1IF1 or later where Internet Explorer 11 is supported for use with iNotes.
However as a possible workaround, you may find that iNotes will work better while in compatibility mode
1. Open Internet Explorer 10 / 11
2. Log into iNotes.
3. From the browser toolbar, click "Tools" -> "Compatibility View Settings"
4. On the pop up box that appears, add your domain then click "Add"
5. Refresh the web page (if it doesn't do it automatically), you should then be able to access webmail.
I hope this information is of assistance.
Kind Regards,
Nessa