I do not have an email address anymore (i.e., long-term leave). How can I log in?

You can enter the unique identifier, this is the same as your EU Institution UserID, of your EU Login account instead of your email, in order to login with your account.

For European Commission users it is usually the first 7 letters of your last name followed by the 2 first letters of your firts name. For other Institutions, the UserID starts with an "i". 

Note that the combination is unique and therefore sometimes letters from the first name may vary slightly (e.g. taking the first and last letters instead) in case the combination existed for a revious account.