Several students have told me that they’ve tried to email me at U.M. but the mail has bounced. At first I was skeptical, since I’m getting email, but one student was kind enough to send me headers, which led me to this CBL Lookup Utility. The CBL is a self-styled “composite blocking list”. They do provide a form for removal, but as I’m not the owner of the machine that has the blocked IP number — it’s upstream from me — I’m not about to try to fill it out.
I reported this to the help desk and they’re “working on it”.
Meanwhile, if mail to me bounces, there is a rarely-used backup: firstname.lastname@example.org (be sure to replace myforename with michael and mysurname with froomkin). I’ll try to check there occasionally.