If it’s from a trusted source, someone that they already know and have given of their email address of their own volition, that’s more than half the battle won. Another 33% will open solely based on the subject line, so you’ve got to be creative, succinct, use verbs and test subject lines. Your industry and day and time will often play a large role. If your industry is directly related to your client’s work, they might just open your email on a Monday. If it is somewhat related, maybe on a Tuesday. Most press releases are sent on a Tuesday, after journalists have had their fill on Monday morning of the top news and Tuesday they have a moment to look at other news.