Similar to how HubSpot suggests certain times for social media posts, it'd be great to have this feature for emails and for it to be specific to your account. So once an email is drafted, HubSpot recommends the best day/time to send based on all of your past email sends. It'd also be great to have something similar to this - some sort of report or graph (like the email health chart) that shows the days that are best for you to send emails and the times per day that are best (based on open and/or CTR).