sendmail MTA

[sanjay dubey]

Hi ,
I am sanjay , I am facing some problem in sendmail MTA,

Let me make you aware about the mail structure, I am using sendmail as
MTA and cyrus-Imap as database. Authentication is happening from
microsoft AD,  with this I am facing follwing problems
1. users are receving some spoof mail mean senders address are getting
changed . Change senders name are also part of global address list .

2. I am not able to check spelling while using squirel mail using html
format mail editor.

I will be thankful  if somebody help .

Cheers
sanjay