Currently, it appears all Pushpage issues must be sent with visible "alternative text" and web viewing link for the issue, which appear at the top of every message. I understand it is possible to edit the text displayed for each of these within OnMessage settings for Pushpage, but industry best practices for many years have included crafting invisible custom preheader text for each message to hint at content in email clients that support this, such as Gmail and iPhone. This is a huge gap in Pushpage. As it stands now, we are forced to send highly generic, uninteresting but visible preview text that can only take readers to an alternative web version, and may possibly deter them from opening our messages (the default "If you are having trouble" alternative text). At the least, we need the option to completely turn off all visible text automatically appended to the top of issues, and even better would be the ability to specify invisible preheader content for an individual issue.