When I'm running XP (fully updated) as a guest system I'm having problems with SMTP on public hotspots: I can receive email on the XP guest virtual machine but I cannot send mails via SMTP. Both the hotspots I tried this on were T-Mobile/T-Online (in Germany). I know that hotspot operators frequently block SMTP sending and port 25 but that is does not appear to be the direct problem in this case, as I can send mails via SMTP with Apple Mail under OSX just fine. It seems that it is being blocked when the SMTP protocol is being routed out from the guest virtual machine -- perhaps this adds additional data to the protocol stream that the server flags as suspicious... I tried playing around with the settings, switching between bridged and shared networking but that didn't help. I also tried varying the SMTP settings, trying both standard port and dedicated port for SSL SMTP and as an experiment also regular non-SSL but none of it worked. Does anyone know a workaround for this problem? I'm using build 5160.
