When using SPUtility.SendEmail to send emails, sometimes it adds spaces and new lines to the email body automatically, or sometimes it even removes some characters, or change < to <.
Add “\n” at the end of each paragraph or at the end of each row of your HTML table.
string emailBody = "<div>Hello,<br /><br />Just letting you know that the CityLink invoice/travel details have been reviewed by all the e-Tag holders.<br /><br />\n";
emailBody += "This is the library and you can view the workflow details here:<br /><br />\n";
emailBody += "<table><tr><th>Name</th><th>ID</th><th>Details</th><th>Date</th></tr>\n";