Automatic avoid frustrating back-to-back meetings when scheduling Outlook appointments. All you have to do is change the default meeting length in Outlook.
Open Outlook then navigate to File -> Options -> Calendar (left menu)
Now locate the Calendar options section and check the “Shorten appointments and meetings”. The most convenient is selecting “End early”. Afterwards you can set the preferred time for less than one hour and longer than one hour. Here you see how it could look like.
I selected End early and having 5 minutes less for less than one hour meetings and 10 minutes for one hour or longer. This will result in meeting of 30 minutes to default being 25min instead and 1 hour meeting will default to 55 minutes instead.
Hurray! We got yourself some time between our meetings! And it only took 30 seconds to setup.
Source: Microsoft Outlook Mail Settings