Vista - Can't send large emails from Windows Live Mail

I am using Windows Live Mail to send to my Verizon and msn accounts. I can receive mail consistently. I can send small mails consistently. If I try to send a larger mail...it gets stuck in the outbox and all subsequent mails stack up behind it.

Right now, there is a 900kB mail in my outbox. If I try to send to my Verizon account, I get a message:

Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity.

Subject 'Fw: Test Message'
Server: 'outgoing.verizon.net'
Windows Live Mail Error ID: 0x800CCC0F
Protocol: SMTP
Port: 25
Secure(SSL): No
Socket Error: 10053

If I try to send to my msn account, I get:

Unable to send or receive messages for the Msn (myaccountname) account. To send and receive messages in your Hotmail account, go to Sign In on the Web, or try again later. To get help from Windows Live Customer Support, go to http://support.live.com and click Windows Live Mail in the list of services.

Subject 'Fw: Test Message'
Windows Live Mail Error ID: 0x80072EFF

I have tried without antivirus, firewall and spyware software running...and no change. I have turned off Vista's autotuning...no change.

Please help!!!!

Have you checked the Verizon's causes and try to have fixed them?
I can't help you much because I don't use Windows Live Mail, though I do use hotmail. It seems for your hotmail account it is saying you haven't logged on though... you were logged on, right? Try going to the listed website for the customer support.

I have tried Verizon's sites to no avail.

I certainly seem to be logged into my Windows Live / hotmail account when receiving and when sending smaller files....it seems to be only when sending large files (of photos).

Ohhh... You're trying to send an attachment... I'm stupid, no wonder the file is so big.
The limit for Windows Live for attachments is 10 MB, which is very little. Does your file surpass that limit? If it does I recommended uploading it to a streaming, such as megaupload and mediafire, site and share the link the the one you want to.

I get message type 1 above when I try to do an SMTP "send" of mail with an attachment of basically any size...I'm down to 20kB attachments and it still does this (simple text mail without attachments go through).

I get message type 2 above when I try to send any size attachment through my http connection in Windows Live Mail to my msn account.

I switched my Windows Live Mail connection from http to pop3/smtp....and now that connection gives me the same "type 1" messages I was getting on my Verizon smtp..even with dinky little attachments

I FINALLY got to the bottom of the problem:

I ran speed tests at Stanford University NDT server I was only getting a pathetic 5 kbps on outbound connections (client to server test in iperf)...I finally found the source of the problem...I had connected my Dish Network satellite receiver phone connection directly to a wall jack without a DSL filter. If I unplugged this connection, normal outbound DSL speeds were immediately shown on my next run of iperf. If I tried to reconnect the satellite receiver phone line...the outbound connection speeds dropped to nothing.

I am so grateful that I will be able to sleep tonight instead of another night of tearing my hair out.

I'm glad you have figured out your answer...
Sorry I didn't help at all, I really did not understand you one bit.