When comparing SmartDay vs Microsoft Outlook, the Slant community recommends SmartDay for most people. In the question“What are the best calendar apps for Mac OS X?” SmartDay is ranked 7th while Microsoft Outlook is ranked 13th. The most important reason people chose SmartDay is:
The app doubles as a task manager and allows dragging and dropping tasks into the calendar on specific days. If a task does not get completed on that day, it automatically gets rescheduled.
Specs
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Pros
Pro Integrates task-management with the calendar
The app doubles as a task manager and allows dragging and dropping tasks into the calendar on specific days. If a task does not get completed on that day, it automatically gets rescheduled.
Pro Aims to provide a complete organizational solution
The app includes a way to manage tasks, take notes, set reminders and manage project from within the calendar.
Pro Calendars can be shared
Pro Good built-in calendar
The calendar includes agenda, day, and three-day views.

Pro Integration with calendar and tasks
Quick conversion of a received email to a task with the deadline.
Pro Fun to use
clean and smooth experience, very nice and i like it.
Pro Smart lookup
Smart lookup is a feature where the Bing search engine is bundled in the app to allow users to automatically search for relevant websites, information and images based on the word highlighted by users, without need to open external browsers. The results will be shown on the right pane of the window.
Pro Priority messages
Microsoft Outlook comes with feature called "Clutter" to filter out incoming email based on the priority of the message set by user. User will be alerted when the high-priority message is incoming, whereas the low-priority message will be put in a separate folder.
Pro Attach files from cloud
Microsoft Outlook allow users to directly attach an attachment directly from cloud services without need to download an entire file before attach to the intended e-mail.
Pro VBA macros
Pro Conditional formatting
Pro Cloud
can attach files and use cloud, very good.
Cons
Con it's not free
not as pricey as others, but still not free.
Con Doesn't integrate
Does not support Google Calendar integration.
Con Support is limited
The app support is confusing and hard to navigate.
Con Lacks natural language input
Natural language input allows creating events in the same way if you had to tell it to a friend. Writing something like "Lunch at 2pm" would add an event called "Lunch" at 2 PM. SmartDay lacks that functionality.
Con It's from Microsoft
Con Rather buggy
Con Crashes frequently
The only issue with Outlook 2017 is that when the Mail folder increases in size, it sometimes crashes for no reason it, causing loss of data.
Con Categorize email IMAP not good
Con Frustrating user experience
The "Clean Interface" approach means that normal and necessary user interface elements have been removed, such as certain scroll bars, and even the "replied to" indicator. This program becomes more frustrating with each new update.
Con No unique Inbox / global folders
Con No portable bundle available
Con No aliases
Outlook does not support email aliases other then outlook aliases
Con The UI is outdated
Con Only available for Windows
