Hi, me again (most unfortunately ;D)

It appears I may have a buggy PM box.
A few days ago while having a chat with somebody over PM, I received a mail notification, but no new mail was revealed in the mailbox. As for now, I have a blinking mail icon all day long which is apparently a ghost mail now.

Nevertheless, I tried relogging to the forum account but that did not help either so I guess I might have to ask for god mods' help again .

The person I was speaking with said that he had sent some 3 mails now yet I still have the 1 blinky mail. There is plenty of mailbox space ever since, too. Also had deleted several mails long before that.
He did note that he had sent one mail via cellphone/smartphone (I suppose) but I doubt that caused the bug.

Anyhow, requesting assistance, bitte. o7