As someone who spent a fair deal of time in sales, this is the worst thing you can do to close an email. You're essentially saying, "If you need me, contact me

As someone who spent a fair deal of time in sales, this is the worst thing you can do to close an email. You're essentially saying, "If you need me, contact me." and allowing the client to just opt out of working with you. In sales, you always had to have a path where you want to lead the client. "Let's put together a time frame for A, B, C and I follow up when A is done." or "Once the budget is approved, we're going to do A, B, and C by this date." It also shows you're invested in the client and invested in what they want to accomplish. It does take extra work to nail down clients, and at times will feel like you're trying to herd cats, but it's quite effective in the long run.