Re: GMail out again today...
Authentication was also problematic yesterday evening: I don't use gmail but send two messages to friends' gmail accounts around 23:00 and got:
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients.
<firstname.lastname@example.org>: host gmail-smtp-in.l.google.com[126.96.36.199] said:
550-5.1.1 The email account that you tried to reach does not exist. Please
try 550-5.1.1 double-checking the recipient's email address for typos or
550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1
https://support.google.com/mail/?p=NoSuchUser cw4si6981ejb.196 - gsmtp (in
reply to RCPT TO command)