@timethief
Yes, still experiencing it. (Thank you for keeping track of me!) Going into the stats just now showed me that I got a new follower two days ago, and I didn't get an email about it.
There's been no new Staff help offered on my problem for the last five days. I even haven't gotten e-mail notices of all the above followup posts since mine of April 9. But I still do get email notices of comments on my blog, so @wordpress.com is not blocked on my system.
If macmanx doesn't have any further ideas, might there be someone more senior on the Staff who could step in at this point? (And who, hopefully, will read the entire thread so as not to re-suggest that I do all the things I've already done several times over.)