What browser are you using?
HTTP 1.1 does not cause a problem with Verizon email.
Pipelining is not implemented or is disabled in most browsers. Opera is the only common one that defaults with it enabled. I don't know if Verizon has a proble with it or not.
Remember you are talking to PEERS.
Another error message
Unable to load /webmail/driver?nimlet=reportspam status:502.
This is an error message FROM THE VERIZON SERVERS.
It appeared as a group of spam messages (about 10 or so), was being sent to spam.
A full refresh of the WebMail browser screen was done to prevent message loss, just in case...
502 Bad Gateway errors are completely independent of your particular setup, meaning that you could see one in any browser, on any operating system, and on any device.
Cause of 502 Bad Gateway Errors
Often, Bad Gateway errors are caused by issues between servers online that you have no control over.
Also remember that Verizon does not give us the opportunity to actually talk to anyone with real knowledge of the system, only to "technicians" that are fed only slighty higher quality information diets than mushrooms. Earnestly try as they might, the vast majority of these people cannot be helpful much beyond canned responses.
This is harmful to those with elusive problems because there is no reliable way to get information to or from knowledgable people. For example, my difficulties were first reported as "Can't get email" completely distorting the problem and perhaps poisioning further efforts to relay useful information.
As a result, we are left to speculate and perform "see if it sticks" troubleshooting. Very poor way for Verizon to run the show!