I am using the PHP mail() function to send a simple HTML-formatted email to an internal address. The only header that I am passing is "From: blah@blah.com\nContent-Type: text/html;\n". The message is generated and sent without a problem, however there are random formatting issues when the message is viewed. It appears that an ! mark is randomly being placed in the body of the message such that if it appears in the middle of a </b>, the cancel bold tag will fail and the remainder of the message will appear. In some cases there will must be a random ! mark in the middle of a block of text. It appears that the character is consistently showing up N characters into the message (I haven't done the math so I'm not quite sure what N is). Any ideas?