Problems to send internal mail - Send HELO instead of EHLO

[murpau]

Hi,

I have big problems to send mails between Exchanges server (only 5.5., 2K and one 2003) in the same network and I try almost everything to fix the problems and the only thing that works is to put on every connector(advanced) "Send HELO instead of EHLO", is this dangerous, will I expose my server to security problems ?

Thank you