Growing number of iCloud users experiencing Mail delivery errors

Apple appears to be experiencing issues with its iCloud Mail service today, as a growing number of users report receiving a delivery error message from postmaster@mac.com for every email received (as pictured above). Most users report still being able to receive emails but also receiving the above error report for each email, while others claim the problem is only happening on specific accounts. An Apple support thread has been started with an increasing number of posters experiencing the same issue since this morning.
Reason: Error in sieve filter: Notify mailto: recipient is not a valid address Action: delivered Status: 2.0.0 (Error in sieve filter: Notify mailto: recipient is not a valid address).
There are also several users on Twitter complaining of the same error, but Apple ha yet to update its system status page to reflect the problems with Mail.
Anybody else using http://t.co/yMNQlQaozp email addresses getting mail delivery error messages after receiving actual emails? It’s annoying!
— Subtle Code Switch Traits (@Tabbulous) March 7, 2013
https://twitter.com/datasaur/status/309705896399863809
Anybody else have 'Problem during delivery processing' from postmaster@mac.com ? #iCloud #Mail #Alias #fail
— John Stoll (@jstoll) March 7, 2013
Apple is keeping mum of their iCloud mail problems, but the infamous "Error in sieve filter" is their issue | http://t.co/9zGxrHVO4K
— cteodor (@cteodor) March 7, 2013
https://twitter.com/arumandox/status/309717313265999874

Apple Senior Vice President Phil Schiller 
Fantastical version 1.1:
Solavei, the T-Mobile MVNO offering $49-per-month unlimited on the carrier’s newly enhanced HSPA+ network, today announced the availability of nano SIM cards for unlocked iPhone 5 owners. That means iPhone 5 customers will now be able to sign up to the unlimited voice, text, and data plans by purchasing a nano SIM direct from Solavei for $9.










The Vancouver Sun reported
Verizon CFO Fran Shammo 
Following a petition on whitehouse.gov that urges the Library of Congress to change its
We reported over the weekend that there was some confusion over 