Hi,
I sent emails to a lot of POIs for other unis but they rarely reply and if they do it’s very vague like ‘Good Luck with your application’ XD
In an email to a POI that actually replied, he told me that he was happy I contacted him and would love to discuss his group and MIT etc. And then whether I was free for an informal Skype chat.
i sent an email to my POI at MIT December right before the Christmas holidays in much the same way as all the other POIs , except this time I added a link to my website and kept the email short and to the point , and he replied enthusiastically. I think one of the reasons may have been that before contacting him I browsed his research groups website and saw that he actively encouraged interested PhD students to get in touch, so he was actually looking for them. A lot of professors may not be looking for PhD students at all for the upcoming year. In hindsight I would ask the POI if they were looking for phd students first before actively engaging them.
A LOT of people said they got admits without interview, check out the results page for MIT* Computer Science. Don’t be discouraged.
I hope that was helpful.