Hubspot has no interest in ever adding this for whatever reason. My company left almost a year ago due to this missing feature.
Hard to believe this request isn’t even being considered. PLEASE implement testing. It’s critical to be able to easily test emails before adding to automation, and the workaround of sending each template to yourself is way too clunky, especially if trying to train and require members to perform basic email testing.
Additionally, and probably a separate idea, but Templates in general are difficult to even locate anywhere outside the sequence. If you are searching for a set of templates that you need to test for a sequence, there is not a way to sort templates by Folder or by those used in specific sequences. So unless you rigourously require your team to use naming conventions when creating templates, they just get lost in a sea of templates. Please consider adding and enhancing these very basic template features.
Hubspot pleaseeeeeeeeee fix this!!!
Five years on the radar now 
I’m not even surprised anymore when I come across these ages old features requests with hundreds of upvotes and comments, but here I am, upvoting and commenting like the rest in the hopes that this ever becomes part of the roadmap. It’s disappointing how often simple, yet essential functionality is absent from frequently-used tools like sales sequences. Can we please have support feeling confident in all the communications we send through HubSpot?
@adimarino @glencornell
Any updates since the last one two years ago?
Agree 100%, this would be a great feature, and I’m suprised it’s not already available
how is this not a thing yet?? lol