I have many contacts from years ago. Can I still contact them?
Yes, you can always reconnect with them. Don’t feel bad that it is from such a long time ago. They didn’t take action either. They probably have the same hesitation as you do.
Especially this time of the year is a good moment to do that.
When you reconnect with them, always make your message personal. Refer to the time you spent together, the projects you worked on or the time in college. Use the name in your invitation message you were known by the time you knew them. This especially applies to women who now go by the name of their husband.
To your success !