推荐信上要留推荐人email等联系方式吗？

如题，谢谢！

私人信箱可以吗，还是说必须要有公司或学校后缀的email地址

Any email should work.  The recommender's position and affiliation is clarified as part of the recommendation.  Just make sure there's no funny words in the email address and it's something that the  recommender checks frequently in case the school contacts him/her.