There are two ways you can accept a meeting request.
1. when you are browsing list mail (and invite isn't opened)
2. wen you have opened the invite
for 1)
When the meeting invite is the focused email
- press SHIFT + F10 this will open the context menu(right click menu of invite)
- now press C again C and ENTER
- now use common response keyboard shortcut
for 2)
- can use ALT + H to navigate to ribbon
- C to do the click effect on pull out accept response option
- now use common response keyboard shortcut (as below)
Common Response Key
both ways once you select accept you can use any of following to respond
- E Edit the response before sending.
- S Send the response now.
- D Don't send a response.