Mailbutler, along with my workflow that includes lots of email responses is great! My favorite feature is holding the mail in a queue before it heads out. It buys you some time before it is sent. Lots of other apps do the same thing but I am reliant on MacMail. Customer Service is awesome and I recommend highly.! I don't use the feature but snoozing is also great for people that need it.
Serious step back in usability. Their configuration web page now replaces the efficient Mail plug-in interface, and this web page is difficult to navigate and lacks several of the features and options previously offered by the plug-in: -- Avatar icons / Contact images in Apple Mail now are virtually non-existent. The previous version was EXCELLENT in locating and displaying user & company avatar icons. -- You now cannot choose the minimum size of attachments to trigger their upload to a cloud service. -- There is now MailButler advertising inserted in every outgoing email if you do not pay them a monthly fee. -- The optional MailButler menu bar icon ("Direct Inbox") now does absolutely nothing when it is clicked. -- This new version of MailButler is incompatible with the QuoteFix Mail plug-in. -- MailButler's Smart Mailboxes in Apple Mail are now gone.
These issues are just what I've discovered in the first 24 hours. I really hope the developer fixes all of these problems ASAP.