I want to make a mail redirect from www.domain1.com to www.domain2.com. The problem is that domain2.com mail is hosted by Google Apps. All my employees have two mails, employeeX@domain1.com hosted in my office and employeeX@domain2.com hosted by GApps. I will turn off office servers when I'm sure that all the mail is redirected, so they only need to use one mail.
I don't know if changing domain1.com MX register to mail.domain2.com will work.
Any suggestion or ideas to make this happens?
Are you planning to shut down domain1.com? If so, I would suggest adding it as a domain alias on your Google Apps account. This will walk you through domain ownership verification as well as updating your MX records.
Once completed, all users in Apps will automatically have an alias @domain1.com. Because of this and the change to MX records, they will continue to receive emails sent to their username@domain1.com right in their inbox for @domain2.com.