<p>There are lots of PHP articles about the subject so is this a PHP only problem.
I am sending emails using System.Net.Mail after some regular expression checks of course.
Similar to <a href="http://weblogs.asp.net/scottgu/archive/2005/12/10/432854.aspx" rel="noreferrer">http://weblogs.asp.net/scottgu/archive/2005/12/10/432854.aspx</a></p>

[{'answer_id': 54906, 'author': 'Community', 'author_id': -1, 'author_profile': 'https://Stackoverflow.com/users/-1', 'pm_score': 2, 'selected': False, 'text': "<p>I've never heard of that issue in ASP.NET.  However, you should trust user input about as much as you'd trust a hooker with your wallet.</p>\n"}, {'answer_id': 54907, 'author': 'Danimal', 'author_id': 2757, 'author_profile': 'https://Stackoverflow.com/users/2757', 'pm_score': 4, 'selected': True, 'text': '<p>the PHP email injection attack works because of a weakness in the PHP Mail() function. As a .net developer you need not worry.</p>\n'}, {'answer_id': 54921, 'author': 'Jon Limjap', 'author_id': 372, 'author_profile': 'https://Stackoverflow.com/users/372', 'pm_score': 2, 'selected': False, 'text': '<p>As long as you are using the <a href="http://msdn.microsoft.com/en-us/library/system.net.mail.mailaddress.aspx" rel="nofollow noreferrer">MailAddress</a> object, I think you\'re fine, because injections will only manage to throw FormatExceptions for the specified address.</p>\n\n<p>Examples of how to properly use the System.Net.Mail components are included in that MSDN page; be sure to follow them and you will be fine.</p>\n'}]
['https://Stackoverflow.com/questions/54889', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/5471/']