Can't send emails. Receive them OK
Started Friday on all devices, including my phone.
On Mozilla Thunderbird I get the following message:
"An error occurred while sending mail. The mail server responded: 5.7.1 We were unable to deliver your message. Please try resending your message by adding some text.. Please check the message and try again."
On Yahoo web I get:
"Unable to send message
I do business on this account and it's critical to me.