Note to self: get someone else to proofread the letters and statements I’m sending to graduate schools.
Somehow I managed to mash together the username for one’s departmental email address and the domain for the main, non-departmental email service from the university (resulting in a syntactically-correct but non-existent) in a cover letter.
I didn’t catch it in my own proofreading, as my brain mentally divided the email into the username and domain parts, and didn’t notice the mismatch. Now I have to write an email to the graduate school apologizing for any confusion and sending them the correct address.