I am periodically getting "Alert" when trying to send emails. Sometimes sending works, then later doesn't work. Receiving always works okay. Only sending text message, no attachments, only to one recipient. The Alert says: ''The size of the message you are trying to send exceeds a temporary size limit of the server. The message was not sent; try to reduce the message size or wait some time and try again. The server responded: 4.7.1 <unknown[my.ip.address]>: Client host rejected: my.ip.address exceeded hourly recipients threshold.'' Seems to me that the error has to be at the server end. I have the same issue on three different computers with different operating systems, and frequently different updates of Thunderbird. When email is working on one system it is working on all; when down on one it's down on all. We are currently Ziply customers since they took over Frontier. But Ziply says it's not their problem since it's a Frontier.com email address; Frontier says it's not their problem since our account is with Ziply. The final conclusion from a pleasant (but possibly clueless) Frontier rep was that the problem is with Thunderbird; the main reason being that sending of email always seems to work via web interface. Any insights appreciated. Thank you.