Hello, I have had a Samsung 4G hotspot (SCH-LC11) for about a year now and have had no problems with it until about the beginning of December 2011. The problem is that while I can connect to the internet, browse the web, and receive email, I suddenly cannot connect to my corporate outgoing mail SMTP server and therefore send email. If I disconnect my laptop from the Verizon 4G card and connect through either my home network (Cable internet), or through the internet connection at any open wifi I happen to be near, it sends email just fine. I also have a Verizon Droid (3g) phone set up to use the same corporate email account and it sends and receives just fine on the 3g network. But if I connect the phone to the 4g wifi hotspot, all of a sudden it will not send just like the laptop. I have also gotten the same results using a tablet and another laptop with the same outgoing email using Mozilla Thunderbird rather than Outlook, so it does not seem to be a problem with the laptop, phone, tablet or other laptop.
My corporate network administrator tells me that while I am connected to the 4g hotspot and trying to send email, he is seeing the following message "SMTP Spam attack from xxx.xxx.xxx.xxx Client sent data before SMTP greeting." (The x's were my ip address).
Verizon has sent me a different (refurbished) Samsung 4g card with newer firmware than my original one had, but that did not fix it. I tried going to a Verizon store and connecting through a Novatel 4510 4g Hotspot at the store and got the same results.
I did find a similar problem here http://www.mypctechs.com/techclub/?p=1003 But that seemed to be on USB devices which use VZ Access Manager and they said that an update to VZ access manager fixed it. Because this is a hotspot, I do not have access manager on anything, nor do I see how access manager on a laptop would affect the hotspot.
The key seems to be the "Client sent data before SMTP greeting" part of the message from the email server, but I don't know where to go from here. Why would the 4g network be sending extra data and how do I get it to stop?