Im looking for help on an odd email problem. I have two computers on the same cable modem, connected to the ISP via an Ethernet hub. Both computers are on WinXP SP2, Asus K8N MoBo. One computer does the following:
When sending an email with an attachment of approximately 3.5MB or larger, Thunderbird gives me the following error: "Sending of message failed. The message could not be sent because connecting to SMTP server smtp.central.cox.net failed. The server may be unavailable or is refusing SMTP connections." Please verify that your SMTP server setting is correct and try again, or else contact your network administrator.
Sending the same file via Outlook Express gives me the following error: Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account pop.central.cox.net', Server: smtp.central.cox.net', Protocol: SMPT, Port 25, Secure(SSL): No, Error Number:
Smaller attachments and emails with no attachments go through both programs with no problems. My ISP has a limit of 10MB. The second computer handles the same attachments with no problems.
I have read a number of the threads regarding the 0x800CCC0F error, they all seem to deal with the inability to send or receive emails regardless of size, my problems seems to be related to the size of the attachment, or timing, or I obviously dont know what. Receiving emails is not a problem.
I have tried a number of things, routing the modem directly to the offending machine, switching cables, completely uninstalling my firewall and antivirus, all to no avail. I have run a telnet test on smtp.central.cox.net, port 25, with no error message.
Any help on this would be greatly appreciated.