I don't know whether this is a bug or not. I have subscribed twice to the Secunia weekly advisories, using pclosmail. In neither case has the 'activation' email reached my inbox.
Do you have the spam filters turned on? Is it in the spam or junk folder?
UPDATE: I just checked my mail log(s) and this is what I found
Dec 9 11:30:17 findmoore postfix/smtpd[14420]: connect from mail.secunia.com[213.150.41.240]
Dec 9 11:30:19 findmoore postfix/smtpd[14420]: NOQUEUE: reject: RCPT from mail.secunia.com[213.150.41.240]: 554 5.1.1
<xxxxxxxxxxx@pclosmail.com>: Recipient address rejected: User unknown in local recipient table; from=<
apache@secunia.com> to=<
xxxxxxxxxxx@pclosmail.com> proto=SMTP helo=<mail.secunia.com>
Dec 9 11:30:19 findmoore postfix/smtpd[14420]: disconnect from mail.secunia.com[213.150.41.240]
Note the part in green. There is no such user as "xxxxxxxxxx". Your username that was set up as "
username" as per your PM sent to me.