too many emails per day
I was trying to send an email and received the message:
"An error occurred while sending mail. The mail server responded:
5.7.1 <firstname.lastname@example.org>: Recipient address rejected: Mehr Mails versandt als der Tarif erlaubt / Too many mails per day.
Please check the message recipient "email@example.com" and try again."
I had only sent one other email to this user and only five total today.
(The email address was replaced for privacy.)