Can recommenders submit their letter via mail, email, fax, or a letter service?

All recommendations must be submitted using the online application system as recommenders are required to respond to specific evaluation questions on the recommendation form. Letters of recommendation cannot be mailed, emailed, faxed, or submitted through a letter service (with the exception of Interfolio). For letters submitted via Interfolio, please remember that letters written specifically for your Stanford graduate program tend to be stronger than letters written for general use purposes.