Socket Error: 10054 after switching DSL providers

[ZeBozette]

We had DSL (actually ADSL I think) that was working without errors. Not a superfast connection but we're 20,000 ft from the CO so we weren't promised much.
We just switched to a different DSL provider who promised us much faster speeds. Now we're unable to send attachments over 500kb. The send begins but stops after about 20 seconds. Then we get this error:
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Subject 'email subject', Account: "acct name', Server: 'smtp.provider.com', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 10054, Error Number: 0x800CCC0F
Any suggestions?

 

[vipergg]

Sometimes you have to mess around with the MTU size , reccomend going to like broadbandreports.com and running their tweak test and they have tools that will allow you to easily modify certin parameters . Is browsing ok speedwise ?

 

[ZeBozette]

Yes, browsing is fine. And if we go through dial-up we can transfer any size file through ftp or attachments in email. It's just uploading through the newer dsl that has problems. I'll check out broadbandreports.com
Thanks much!