I have IMAP accounts in Mail connected to two different hosting accounts. All of the accounts in Mail can receive emails but the IMAP accounts connected to one hosting account can't send emails from Mail. The email that won't work is from a hosting account at Unlimited Hosting - http://www.unlimitedwebhosting.co.uk As it's one email account that won't send I'm assuming it's that account's SMTP settings. My ISP have told me that SSL needs to be deselected. If I try to deselect it, it selects itself straight away. To stop this I'm using the custom port 587. I have Authentication set to password. My ISP says all my settings are correct. The connection Doctor shows everything connected. I have read all posts about this but still can't get this to work. Can ANYONE offer any advice how I might get this to work. Would deleting and reinstalling Mail be an idea.